diff --git "a/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 III-1306.js" "b/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 III-1306.js" new file mode 100644 index 0000000..73d910e --- /dev/null +++ "b/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 III-1306.js" @@ -0,0 +1,27 @@ +/** + * @param {number[]} arr + * @param {number} start + * @return {boolean} + */ +let canReach = function (arr, start) { + let n = arr.length + let visited = [] + let queue = [start] + while (queue.length) { + let index = queue.pop() + let val = arr[index] + if (val === 0) { + return true + } + let left = index - val + let right = index + val + if (left >= 0 && !visited[left]) { + queue.push(left) + } + if (right < n && !visited[right]) { + queue.push(right) + } + visited[index] = true + } + return false +}; \ No newline at end of file diff --git "a/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 IV-1345.js" "b/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 IV-1345.js" new file mode 100644 index 0000000..be115b2 --- /dev/null +++ "b/BFS\351\227\256\351\242\230/\350\267\263\350\267\203\346\270\270\346\210\217 IV-1345.js" @@ -0,0 +1,72 @@ +/** + * @param {number[]} arr + * @return {number} + */ +let minJumps = function (arr) { + let n = arr.length + if (n === 1) { + return 0 + } + + // 连续出现超过两次的数字就抛弃掉 + let newArr = [] + let sameCount = 0 + for (let i = 0; i < arr.length; i++) { + if (arr[i] === arr[i - 1]) { + sameCount += 1 + if (sameCount >= 2) { + continue + } else { + newArr.push(arr[i]) + } + } else { + newArr.push(arr[i]) + sameCount = 0 + } + } + arr = newArr + n = arr.length + // 遍历一遍 记录每个数字出现的下标位置 + let indexesMap = new Map() + for (let i = 0; i < n; i++) { + let val = arr[i] + let indexes = indexesMap.get(val) + if (!indexes) { + indexesMap.set(val, [i]) + } else { + indexes.push(i) + } + } + + let visited = [] + let count = 0 + let queue = [0] + while (queue.length) { + count++ + let len = queue.length + for (let i = 0; i < len; i++) { + let index = queue.shift() + // 找到了 由于bfs的特性 此时用的跳跃次数一定是最少的 + if (index === n - 1) { + return count - 1 + } + + // 没找到 继续把可以跳的几个位置都放入队列中 + let val = arr[index] + let left = index - 1 + let right = index + 1 + let sameIndexes = indexesMap.get(val) + + if (left >= 0 && !visited[left]) queue.push(left) + if (right < n && !visited[right]) queue.push(right) + for (let sameIndex of sameIndexes) { + if (sameIndex !== index && !visited[sameIndex]) { + queue.push(sameIndex) + } + } + + visited[index] = true + } + } + return n +} diff --git a/README.md b/README.md index c2fd139..11f4963 100644 --- a/README.md +++ b/README.md @@ -7,6 +7,13 @@ > 力扣的题解记录(JavaScript) +## 关于我 +大家好,我是 ssh,现在在字节跳动的 Web Infra 担任前端工程师,微信:**[sshsunlight](https://p1-juejin.byteimg.com/tos-cn-i-k3u1fbpfcp/017d568dc1d14cd883cc3238350a39ec~tplv-k3u1fbpfcp-watermark.image)**,欢迎找我交个朋友。 + +一些算法相关的资料,我放在「前端从进阶到入院」公众号里了,回复「资料」即可获取。 + +![qrcode_for_gh_d2b31290dd8b_258](https://user-images.githubusercontent.com/23615778/134800856-9a44fa9a-4f1b-4884-a0b6-b58c5f3331df.jpg) + ## 调试 提供了 .vscode 配置文件,在 vscode 中选择「小爬虫」图标,点击启动程序,即可启动断点调试。 @@ -15,6 +22,323 @@ 思路会记录在本仓库的 Issues 中,按照 label 进行分类。比如想查看 「DFS」 分类下的问题,那么选择标签进行筛选即可。 +## 目录 + + +### 例题详解 + +[最接近的三数之和-16](https://github.com/sl1673495/leetcode-javascript/issues/115) + +[分发饼干-455](https://github.com/sl1673495/leetcode-javascript/issues/88) + +[N皇后-51](https://github.com/sl1673495/leetcode-javascript/issues/78) + +[单词搜索-79](https://github.com/sl1673495/leetcode-javascript/issues/77) + +[二进制手表-401](https://github.com/sl1673495/leetcode-javascript/issues/76) + +[电话号码的字母组合-17](https://github.com/sl1673495/leetcode-javascript/issues/65) + +[二叉树的所有路径-257](https://github.com/sl1673495/leetcode-javascript/issues/59) + +[路径总和-112](https://github.com/sl1673495/leetcode-javascript/issues/57) + +[两两交换链表中的节点-24](https://github.com/sl1673495/leetcode-javascript/issues/51) + +[有效的括号-20](https://github.com/sl1673495/leetcode-javascript/issues/48) + +[无重复字符的最长子串-3](https://github.com/sl1673495/leetcode-javascript/issues/42) + +[二分查找-704](https://github.com/sl1673495/leetcode-javascript/issues/23) + +### 递归与回溯 + +[跳水板-面试题 16.11 ](https://github.com/sl1673495/leetcode-javascript/issues/118) + +[顺次数-1291](https://github.com/sl1673495/leetcode-javascript/issues/116) + +[螺旋矩阵 II-59](https://github.com/sl1673495/leetcode-javascript/issues/113) + +[螺旋矩阵-54](https://github.com/sl1673495/leetcode-javascript/issues/112) + +[矩阵置零-73](https://github.com/sl1673495/leetcode-javascript/issues/111) + +[不同路径 III-980](https://github.com/sl1673495/leetcode-javascript/issues/107) + +[字母大小写全排列-784](https://github.com/sl1673495/leetcode-javascript/issues/106) + +[黄金矿工-1219](https://github.com/sl1673495/leetcode-javascript/issues/105) + +[有重复字符串的排列组合-面试题 08.08](https://github.com/sl1673495/leetcode-javascript/issues/104) + +[单词搜索 II-212](https://github.com/sl1673495/leetcode-javascript/issues/92) + +[解数独-37](https://github.com/sl1673495/leetcode-javascript/issues/79) + +[N皇后-51](https://github.com/sl1673495/leetcode-javascript/issues/78) + +[单词搜索-79](https://github.com/sl1673495/leetcode-javascript/issues/77) + +[二进制手表-401](https://github.com/sl1673495/leetcode-javascript/issues/76) + +[子集 II-90](https://github.com/sl1673495/leetcode-javascript/issues/75) + +[ 组合总和 III-216](https://github.com/sl1673495/leetcode-javascript/issues/74) + +[组合总和 II-40](https://github.com/sl1673495/leetcode-javascript/issues/73) + +[组合总和-39](https://github.com/sl1673495/leetcode-javascript/issues/72) + +[子集-78](https://github.com/sl1673495/leetcode-javascript/issues/71) + +[组合-77](https://github.com/sl1673495/leetcode-javascript/issues/70) + +[全排列 II-47](https://github.com/sl1673495/leetcode-javascript/issues/69) + +[全排列-46](https://github.com/sl1673495/leetcode-javascript/issues/68) + +[分割回文串-131](https://github.com/sl1673495/leetcode-javascript/issues/67) + +[复原IP地址-93](https://github.com/sl1673495/leetcode-javascript/issues/66) + +[电话号码的字母组合-17](https://github.com/sl1673495/leetcode-javascript/issues/65) + +[括号生成-22](https://github.com/sl1673495/leetcode-javascript/issues/31) + +### 动态规划 + +[最长的斐波那契子序列的长度-873](https://github.com/sl1673495/leetcode-javascript/issues/117) + +[最长重复子数组-718](https://github.com/sl1673495/leetcode-javascript/issues/114) + +[下降路径最小和-931](https://github.com/sl1673495/leetcode-javascript/issues/108) + +[最大正方形-221](https://github.com/sl1673495/leetcode-javascript/issues/101) + +[恢复空格-面试题 17.13](https://github.com/sl1673495/leetcode-javascript/issues/100) + +[最长单词-面试题 17.15](https://github.com/sl1673495/leetcode-javascript/issues/99) + +[单词拆分 II-140](https://github.com/sl1673495/leetcode-javascript/issues/95) + +[单词拆分-139](https://github.com/sl1673495/leetcode-javascript/issues/93) + +[最长回文子串-5](https://github.com/sl1673495/leetcode-javascript/issues/91) + +[无重叠区间-435](https://github.com/sl1673495/leetcode-javascript/issues/90) + +[目标和-494](https://github.com/sl1673495/leetcode-javascript/issues/87) + +[一和零-474](https://github.com/sl1673495/leetcode-javascript/issues/86) + +[最长公共子序列-1143](https://github.com/sl1673495/leetcode-javascript/issues/85) + +[摆动序列-376](https://github.com/sl1673495/leetcode-javascript/issues/84) + +[最长上升子序列-300](https://github.com/sl1673495/leetcode-javascript/issues/83) + +[最长等差数列-1027](https://github.com/sl1673495/leetcode-javascript/issues/82) + +[解码方法-91](https://github.com/sl1673495/leetcode-javascript/issues/81) + +[三角形最小路径和-120](https://github.com/sl1673495/leetcode-javascript/issues/80) + +[最小路径和-64](https://github.com/sl1673495/leetcode-javascript/issues/34) + +[括号生成-22](https://github.com/sl1673495/leetcode-javascript/issues/31) + +[爬楼梯-70](https://github.com/sl1673495/leetcode-javascript/issues/22) + +[买卖股票的最佳时机-121](https://github.com/sl1673495/leetcode-javascript/issues/19) + +### 双指针 + +[最接近的三数之和-16](https://github.com/sl1673495/leetcode-javascript/issues/115) + +[通过删除字母匹配到字典里最长单词-524](https://github.com/sl1673495/leetcode-javascript/issues/98) + +[搜索二维矩阵 II-240](https://github.com/sl1673495/leetcode-javascript/issues/96) + +[判断子序列-392](https://github.com/sl1673495/leetcode-javascript/issues/89) + +[分发饼干-455](https://github.com/sl1673495/leetcode-javascript/issues/88) + +[验证回文串-125](https://github.com/sl1673495/leetcode-javascript/issues/33) + +[两数之和 II - 输入有序数组-167](https://github.com/sl1673495/leetcode-javascript/issues/32) + +[合并两个有序数组-88](https://github.com/sl1673495/leetcode-javascript/issues/29) + +[移动零-283](https://github.com/sl1673495/leetcode-javascript/issues/26) + +### 前缀和 + +[和为K的子数组-560](https://github.com/sl1673495/leetcode-javascript/issues/110) + +### 位运算 + +[找不同-389](https://github.com/sl1673495/leetcode-javascript/issues/109) + +### 查找表 + +[找不同-389](https://github.com/sl1673495/leetcode-javascript/issues/109) + +[两个数组的交集 II-350](https://github.com/sl1673495/leetcode-javascript/issues/37) + +### BFS + +[跳跃游戏 IV-1345](https://github.com/sl1673495/leetcode-javascript/issues/103) + +[跳跃游戏 III-1306](https://github.com/sl1673495/leetcode-javascript/issues/102) + +[二叉树的最小深度-111](https://github.com/sl1673495/leetcode-javascript/issues/54) + +[二叉树的最大深度-104](https://github.com/sl1673495/leetcode-javascript/issues/53) + +[二叉树的右视图-199](https://github.com/sl1673495/leetcode-javascript/issues/52) + +[二叉树的层序遍历-102](https://github.com/sl1673495/leetcode-javascript/issues/30) + +[相同的树-100](https://github.com/sl1673495/leetcode-javascript/issues/21) + +### 排序 + +[最长单词-面试题 17.15](https://github.com/sl1673495/leetcode-javascript/issues/99) + +[通过删除字母匹配到字典里最长单词-524](https://github.com/sl1673495/leetcode-javascript/issues/98) + +[快速排序](https://github.com/sl1673495/leetcode-javascript/issues/41) + +[颜色分类-75](https://github.com/sl1673495/leetcode-javascript/issues/28) + +### 链表 + +[移除链表元素-203](https://github.com/sl1673495/leetcode-javascript/issues/97) + +[两数相加-3](https://github.com/sl1673495/leetcode-javascript/issues/94) + +[两两交换链表中的节点-24](https://github.com/sl1673495/leetcode-javascript/issues/51) + +[删除链表的倒数第N个节点-19](https://github.com/sl1673495/leetcode-javascript/issues/46) + +[删除链表的节点-面试题18](https://github.com/sl1673495/leetcode-javascript/issues/40) + +[反转链表II-92](https://github.com/sl1673495/leetcode-javascript/issues/39) + +[反转链表 206](https://github.com/sl1673495/leetcode-javascript/issues/38) + +### 贪心算法 + +[判断子序列-392](https://github.com/sl1673495/leetcode-javascript/issues/89) + +[分发饼干-455](https://github.com/sl1673495/leetcode-javascript/issues/88) + +[买卖股票的最佳时机 II-122](https://github.com/sl1673495/leetcode-javascript/issues/20) + +### DFS + +[二叉树的最近公共祖先-236](https://github.com/sl1673495/leetcode-javascript/issues/64) + +[将有序数组转换为二叉搜索树](https://github.com/sl1673495/leetcode-javascript/issues/63) + +[删除二叉搜索树中的节点-450](https://github.com/sl1673495/leetcode-javascript/issues/62) + +[路径总和 III-437](https://github.com/sl1673495/leetcode-javascript/issues/61) + +[求根到叶子节点数字之和-129](https://github.com/sl1673495/leetcode-javascript/issues/60) + +[二叉树的所有路径-257](https://github.com/sl1673495/leetcode-javascript/issues/59) + +[左叶子之和-404](https://github.com/sl1673495/leetcode-javascript/issues/58) + +[路径总和-112](https://github.com/sl1673495/leetcode-javascript/issues/57) + +[平衡二叉树-110](https://github.com/sl1673495/leetcode-javascript/issues/56) + +[对称二叉树-101](https://github.com/sl1673495/leetcode-javascript/issues/55) + +[二叉树的最小深度-111](https://github.com/sl1673495/leetcode-javascript/issues/54) + +[二叉树的最大深度-104](https://github.com/sl1673495/leetcode-javascript/issues/53) + +[二叉树的层序遍历-102](https://github.com/sl1673495/leetcode-javascript/issues/30) + +[路径总和 II-113](https://github.com/sl1673495/leetcode-javascript/issues/27) + +[相同的树-100](https://github.com/sl1673495/leetcode-javascript/issues/21) + +### 二叉树 + +[二叉树的最近公共祖先-236](https://github.com/sl1673495/leetcode-javascript/issues/64) + +[将有序数组转换为二叉搜索树](https://github.com/sl1673495/leetcode-javascript/issues/63) + +[删除二叉搜索树中的节点-450](https://github.com/sl1673495/leetcode-javascript/issues/62) + +[路径总和 III-437](https://github.com/sl1673495/leetcode-javascript/issues/61) + +[求根到叶子节点数字之和-129](https://github.com/sl1673495/leetcode-javascript/issues/60) + +[二叉树的所有路径-257](https://github.com/sl1673495/leetcode-javascript/issues/59) + +[左叶子之和-404](https://github.com/sl1673495/leetcode-javascript/issues/58) + +[路径总和-112](https://github.com/sl1673495/leetcode-javascript/issues/57) + +[平衡二叉树-110](https://github.com/sl1673495/leetcode-javascript/issues/56) + +[对称二叉树-101](https://github.com/sl1673495/leetcode-javascript/issues/55) + +[二叉树的最小深度-111](https://github.com/sl1673495/leetcode-javascript/issues/54) + +[二叉树的最大深度-104](https://github.com/sl1673495/leetcode-javascript/issues/53) + +[二叉树的右视图-199](https://github.com/sl1673495/leetcode-javascript/issues/52) + +[二叉树的前序遍历-144](https://github.com/sl1673495/leetcode-javascript/issues/50) + +[二叉树的层序遍历-102](https://github.com/sl1673495/leetcode-javascript/issues/30) + +[路径总和 II-113](https://github.com/sl1673495/leetcode-javascript/issues/27) + +[相同的树-100](https://github.com/sl1673495/leetcode-javascript/issues/21) + +### 栈和队列 + +[二叉树的右视图-199](https://github.com/sl1673495/leetcode-javascript/issues/52) + +[二叉树的前序遍历-144](https://github.com/sl1673495/leetcode-javascript/issues/50) + +[简化路径-71](https://github.com/sl1673495/leetcode-javascript/issues/49) + +[有效的括号-20](https://github.com/sl1673495/leetcode-javascript/issues/48) + +[逆波兰表达式求值-150](https://github.com/sl1673495/leetcode-javascript/issues/47) + +### 滑动窗口 + +[滑动窗口的最大值-239](https://github.com/sl1673495/leetcode-javascript/issues/45) + +[找到字符串中所有字母异位词-438](https://github.com/sl1673495/leetcode-javascript/issues/44) + +[最小覆盖子串-76](https://github.com/sl1673495/leetcode-javascript/issues/43) + +[无重复字符的最长子串-3](https://github.com/sl1673495/leetcode-javascript/issues/42) + +[长度最小的子数组-209](https://github.com/sl1673495/leetcode-javascript/issues/36) + +### 数据结构 + +[LRU 缓存机制-146](https://github.com/sl1673495/leetcode-javascript/issues/35) + +### 二分查找 + +[Pow(x, n)-50](https://github.com/sl1673495/leetcode-javascript/issues/25) + +[x 的平方根-69](https://github.com/sl1673495/leetcode-javascript/issues/24) + +[二分查找-704](https://github.com/sl1673495/leetcode-javascript/issues/23) + ## Author 👤 **ssh** diff --git "a/\344\272\214\345\217\211\346\240\221/\344\272\214\345\217\211\346\240\221\347\232\204\346\234\200\350\277\221\345\205\254\345\205\261\347\245\226\345\205\210.js" "b/\344\272\214\345\217\211\346\240\221/\344\272\214\345\217\211\346\240\221\347\232\204\346\234\200\350\277\221\345\205\254\345\205\261\347\245\226\345\205\210.js" new file mode 100644 index 0000000..5067d3c --- /dev/null +++ "b/\344\272\214\345\217\211\346\240\221/\344\272\214\345\217\211\346\240\221\347\232\204\346\234\200\350\277\221\345\205\254\345\205\261\347\245\226\345\205\210.js" @@ -0,0 +1,57 @@ +let T = require("../工具/二叉树") + +let lowestCommonAncestor = function (root, p, q) { + let findAndCreate = (node, target, depth) => { + if (node !== target) { + let findInLeft + if (node.left) { + node.left.parent = node + findInLeft = findAndCreate(node.left, target, depth + 1) + } + + if (findInLeft) { + return findInLeft + } else { + if (node.right) { + node.right.parent = node + return findAndCreate(node.right, target, depth + 1) + } + } + } else { + return { + depth, + node, + } + } + } + + let findP = findAndCreate(root, p, 0) || {} + let findQ = findAndCreate(root, q, 0) || {} + + let cur = findP.depth > findQ.depth ? findQ.node : findP.node + + while (!(isAncestor(cur, p) && isAncestor(cur, q))) { + cur = cur.parent + } + + return cur +} + +function isAncestor(node, target) { + if (!node) { + return false + } + if (node !== target) { + return !!(isAncestor(node.left, target) || isAncestor(node.right, target)) + } else { + return true + } +} + +let l +let r +let t = new T(3) +t.left = l = new T(5) +t.right = r = new T(1) + +console.log(lowestCommonAncestor(t, l, r)) diff --git "a/\344\275\215\350\277\220\347\256\227/\346\211\276\344\270\215\345\220\214-389.js" "b/\344\275\215\350\277\220\347\256\227/\346\211\276\344\270\215\345\220\214-389.js" new file mode 100644 index 0000000..f21e453 --- /dev/null +++ "b/\344\275\215\350\277\220\347\256\227/\346\211\276\344\270\215\345\220\214-389.js" @@ -0,0 +1,15 @@ +/** + * @param {string} s + * @param {string} t + * @return {character} + */ +let findTheDifference = function (s, t) { + let rest = t.charCodeAt(t.length - 1) + for (let i = 0; i < s.length; i++) { + let charS = s[i] + let charT = t[i] + rest ^= charS.charCodeAt(0) + rest ^= charT.charCodeAt(0) + } + return String.fromCharCode(rest) +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\200\345\222\214\351\233\266-474.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\200\345\222\214\351\233\266-474.js" new file mode 100644 index 0000000..69f703a --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\200\345\222\214\351\233\266-474.js" @@ -0,0 +1,49 @@ +/** + * @param {string[]} strs + * @param {number} m + * @param {number} n + * @return {number} + */ +let findMaxForm = function (strs, m, n) { + let sl = strs.length + if (!sl) { + return 0 + } + + let dp = [] + + for (let i = 0; i <= m; i++) { + dp[i] = [] + for (let j = 0; j <= n; j++) { + dp[i][j] = [] + for (let s = 0; s < sl; s++) { + let str = strs[s] + let [strM, strN] = countMAndN(str) + + let pickOnlyPrev = dp[i][j][s - 1] || 0 + let pickCurAndPrev = 0 + if (i >= strM && j >= strN) { + pickCurAndPrev = 1 + (dp[i - strM][j - strN][s - 1] || 0) + } + + dp[i][j][s] = Math.max(pickCurAndPrev, pickOnlyPrev) + } + } + } + return dp[m][n][sl - 1] +} + +function countMAndN(str) { + let m = 0 + let n = 0 + for (let i = 0; i < str.length; i++) { + if (str[i] === "0") { + m++ + } else { + n++ + } + } + return [m, n] +} + +console.log(findMaxForm(["10", "0", "1"], 1, 1)) diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\211\350\247\222\345\275\242\347\232\204\346\234\200\345\260\217\350\267\257\345\276\204\345\222\214-120.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\211\350\247\222\345\275\242\347\232\204\346\234\200\345\260\217\350\267\257\345\276\204\345\222\214-120.js" new file mode 100644 index 0000000..b802d89 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\211\350\247\222\345\275\242\347\232\204\346\234\200\345\260\217\350\267\257\345\276\204\345\222\214-120.js" @@ -0,0 +1,28 @@ +/** + * @param {number[][]} triangle + * @return {number} + */ +let minimumTotal = function (triangle) { + let tryMin = (level, lastIndex, prevSum) => { + if (level === triangle.length) { + return prevSum + } + + let row = triangle[level] + let cur = row[lastIndex] + let curNext = row[lastIndex + 1] + + let selected = tryMin(level + 1, lastIndex, prevSum + cur) + if (curNext !== undefined) { + selected = Math.min( + selected, + tryMin(level + 1, lastIndex + 1, prevSum + curNext) + ) + } + return selected + } + + return tryMin(0, 0, 0) +} + +minimumTotal([[2], [3, 4], [6, 5, 7], [4, 1, 8, 3]]) diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\213\351\231\215\350\267\257\345\276\204\346\234\200\345\260\217\345\222\214-931.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\213\351\231\215\350\267\257\345\276\204\346\234\200\345\260\217\345\222\214-931.js" new file mode 100644 index 0000000..30ef633 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\344\270\213\351\231\215\350\267\257\345\276\204\346\234\200\345\260\217\345\222\214-931.js" @@ -0,0 +1,34 @@ +/** + * @param {number[][]} A + * @return {number} + */ +let minFallingPathSum = function (A) { + let n = A.length + + let dp = [] + for (let i = 0; i < n; i++) { + dp[i] = [] + } + + for (let j = 0; j < n; j++) { + dp[n - 1][j] = A[n - 1][j] + } + + for (let i = n - 2; i >= 0; i--) { + for (let j = 0; j < n; j++) { + dp[i][j] = Infinity + let left = j - 1 + let right = j + 1 + let mid = j + let nextRowIndexes = [left, mid, right] + for (let nextRowIndex of nextRowIndexes) { + if (nextRowIndex >= 0 && nextRowIndex < n) { + dp[i][j] = Math.min(dp[i][j], A[i][j] + dp[i + 1][nextRowIndex]) + } + } + } + } + + // 第一行的最小值 可以确定整体的最小路径 + return Math.min(...dp[0]) +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206 II.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206 II.js" new file mode 100644 index 0000000..06c432a --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206 II.js" @@ -0,0 +1,37 @@ +let wordBreak = function (s, wordDict) { + let uniqSChars = uniq(s.split("")) + let uniqWordDictChars = uniq(wordDict.join("")) + if (uniqSChars.length !== uniqWordDictChars.length) { + return false + } + + let n = s.length + if (!n) { + return [] + } + + let wordSet = new Set(wordDict) + let dp = [] + dp[0] = [""] + + for (let i = 1; i <= n; i++) { + let res = [] + for (let j = i; j >= 0; j--) { + let word = s.slice(j, i) + if (wordSet.has(word)) { + if (dp[j] && dp[j].length) { + for (let prev of dp[j]) { + res.push(prev ? prev + " " + word : word) + } + } + } + } + dp[i] = res + } + + return dp[n] +} + +function uniq(arr) { + return Array.from(new Set(arr)) +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206-139.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206-139.js" new file mode 100644 index 0000000..dbb4672 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\345\215\225\350\257\215\346\213\206\345\210\206-139.js" @@ -0,0 +1,25 @@ +/** + * @param {string} s + * @param {string[]} wordDict + * @return {boolean} + */ +let wordBreak = function (s, wordDict) { + let n = s.length + if (!n) return true + + let wordSet = new Set(wordDict) + let dp = [] + dp[0] = true + + for (let i = 0; i <= n; i++) { + for (let j = i; j >= 0; j--) { + let word = s.slice(j, i) + if (wordSet.has(word) && dp[j]) { + dp[i] = true + break + } + } + } + + return !!dp[n] +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\201\242\345\244\215\347\251\272\346\240\274-\351\235\242\350\257\225\351\242\230 17.13.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\201\242\345\244\215\347\251\272\346\240\274-\351\235\242\350\257\225\351\242\230 17.13.js" new file mode 100644 index 0000000..676d151 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\201\242\345\244\215\347\251\272\346\240\274-\351\235\242\350\257\225\351\242\230 17.13.js" @@ -0,0 +1,19 @@ +/** + * @param {string[]} dictionary + * @param {string} sentence + * @return {number} + */ +let respace = function (dictionary, sentence) { + let n = sentence.length + let dp = [0] + for (let i = 1; i <= n; i++) { + let min = dp[i - 1] + 1 + for (let word of dictionary) { + if (sentence.substring(i - word.length, i) === word) { + min = Math.min(min, dp[i - word.length]) + } + } + dp[i] = min + } + return dp[n] +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\227\240\351\207\215\345\217\240\345\214\272\351\227\264-435.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\227\240\351\207\215\345\217\240\345\214\272\351\227\264-435.js" new file mode 100644 index 0000000..c95bbf1 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\227\240\351\207\215\345\217\240\345\214\272\351\227\264-435.js" @@ -0,0 +1,31 @@ +/** + * @param {number[][]} intervals + * @return {number} + */ +let eraseOverlapIntervals = function (intervals) { + let n = intervals.length + if (!n) { + return 0 + } + + // 按照起始点排序 + intervals.sort((a, b) => a[0] - b[0]) + + // dp[i] 表示从 [0, i] 能构成的最长的无重叠区间的个数 + let dp = [] + dp[0] = 1 + + for (let i = 1; i < n; i++) { + let max = 1 + let [curStart] = intervals[i] + for (let j = 0; j < i; j++) { + let [prevStart, prevEnd] = intervals[j] + if (prevEnd <= curStart) { + max = Math.max(max, dp[j] + 1) + } + } + dp[i] = max + } + + return n - Math.max(...dp) +}; \ No newline at end of file diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\345\244\247\346\255\243\346\226\271\345\275\242-221.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\345\244\247\346\255\243\346\226\271\345\275\242-221.js" new file mode 100644 index 0000000..26c4815 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\345\244\247\346\255\243\346\226\271\345\275\242-221.js" @@ -0,0 +1,44 @@ +/** + * @param {character[][]} matrix + * @return {number} + */ +let maximalSquare = function (matrix) { + let maxY = matrix.length + if (!maxY) return 0 + let maxX = matrix[0].length + + let dp = [] + let max = 0 + + let dpBasic = (y, x) => { + if (matrix[y][x] === "1") { + max = 1 + dp[y][x] = 1 + } else { + dp[y][x] = 0 + } + } + for (let y = 0; y < maxY; y++) { + dp[y] = [] + dpBasic(y, 0) + } + for (let x = 1; x < maxX; x++) { + dpBasic(0, x) + } + + for (let y = 1; y < maxY; y++) { + for (let x = 1; x < maxX; x++) { + let val = matrix[y][x] + if (val === "0") { + dp[y][x] = 0 + } else { + let left = dp[y][x - 1] + let top = dp[y - 1][x] + let leftTop = dp[y - 1][x - 1] + dp[y][x] = Math.min(left, top, leftTop) + 1 + max = Math.max(max, dp[y][x]) + } + } + } + return max * max +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227-300.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227-300.js" new file mode 100644 index 0000000..622c453 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\344\270\212\345\215\207\345\255\220\345\272\217\345\210\227-300.js" @@ -0,0 +1,28 @@ +/** + * @param {number[]} nums + * @return {number} + */ +let lengthOfLIS = function (nums) { + let dp = [] + let n = nums.length + if (!n) { + return 0 + } + + dp[0] = 1 + for (let i = 1; i < n; i++) { + let num = nums[i] + let max = 1 + // j 从 [0, i) 依次求出可以和 i 组成的最长上升子序列 + for (let j = 0; j < i; j++) { + let prevNum = nums[j] + if (num > prevNum) { + // 循环中不断更新 max 值 + max = Math.max(max, dp[j] + 1) + } + } + dp[i] = max + } + + return Math.max(...dp) +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\205\254\345\205\261\345\255\220\345\272\217\345\210\227-1143.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\205\254\345\205\261\345\255\220\345\272\217\345\210\227-1143.js" new file mode 100644 index 0000000..71c8e51 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\205\254\345\205\261\345\255\220\345\272\217\345\210\227-1143.js" @@ -0,0 +1,32 @@ +/** + * @param {string} text1 + * @param {string} text2 + * @return {number} + */ +let longestCommonSubsequence = function (text1, text2) { + let n1 = text1.length + let n2 = text2.length + + let dp = [] + + for (let i1 = 0; i1 <= n1; i1++) { + dp[i1] = [] + dp[i1][0] = 0 + } + dp[0] = Array(n2 + 1).fill(0) + + for (let i1 = 1; i1 <= n1; i1++) { + for (let i2 = 1; i2 <= n2; i2++) { + let str1 = text1[i1 - 1] + let str2 = text2[i2 - 1] + + if (str1 === str2) { + dp[i1][i2] = 1 + dp[i1 - 1][i2 - 1] + }else { + dp[i1][i2] = Math.max(dp[i1 - 1][i2], dp[i1][i2 - 1]) + } + } + } + + return dp[n1][n2] +}; \ No newline at end of file diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\215\225\350\257\215-\351\235\242\350\257\225\351\242\230 17.15.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\215\225\350\257\215-\351\235\242\350\257\225\351\242\230 17.15.js" new file mode 100644 index 0000000..fe82f42 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\215\225\350\257\215-\351\235\242\350\257\225\351\242\230 17.15.js" @@ -0,0 +1,49 @@ +/** + * @param {string} s + * @param {string[]} wordDict + * @return {boolean} + */ +let wordBreak = function (s, wordDict) { + let n = s.length + if (!n) return true + + let wordSet = new Set(wordDict) + let dp = [] + dp[0] = true + + for (let i = 0; i <= n; i++) { + for (let j = i; j >= 0; j--) { + let word = s.slice(j, i) + if (wordSet.has(word) && dp[j]) { + dp[i] = true + break + } + } + } + + return !!dp[n] +} +/** + * @param {string[]} words + * @return {string} + */ +let longestWord = function (words) { + // 先长度降序 后字典序升序 排序 + words.sort((a, b) => { + let diff = b.length - a.length + if (diff !== 0) { + return diff + } else { + return a < b ? -1 : 1 + } + }) + words = Array.from(new Set(words)) + for (let i = 0; i < words.length; i++) { + let word = words[i] + let rest = words.slice(0, i).concat(words.slice(i + 1)) + if (wordBreak(word, rest)) { + return word + } + } + return "" +} \ No newline at end of file diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\233\236\346\226\207\345\255\220\344\270\262-5.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\233\236\346\226\207\345\255\220\344\270\262-5.js" new file mode 100644 index 0000000..9876ba0 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\345\233\236\346\226\207\345\255\220\344\270\262-5.js" @@ -0,0 +1,77 @@ +/** + * 动态规划 + * @param {string} s + * @return {string} + */ +// let longestPalindrome = function (s) { +// let n = s.length +// if (n < 2) { +// return s +// } + +// let dp = [] +// for (let i = 0; i < n; i++) { +// dp[i] = [] +// dp[i][i] = true +// } + +// let max = 0 +// let begin = 0 +// for (let j = 1; j < n; j++) { +// for (let i = 0; i < j; i++) { +// if (s[j] !== s[i]) { +// dp[i][j] = false +// } else { +// let indent = dp[i + 1][j - 1] +// if (indent === undefined || indent === true) { +// dp[i][j] = true +// }else { +// dp[i][j] = false +// } +// } + +// if (dp[i][j] === true && j - i > max) { +// max = j - i +// begin = i +// } +// } +// } +// console.log('dp', dp) +// return s.substr(begin, max + 1) +// } + +/** + * 中心扩散法 + * @param {string} s + * @return {string} + */ +let longestPalindrome = function (s) { + let n = s.length + if (n < 2) { + return s + } + + let begin = 0 + let max = 1 + + let spread = (start, end) => { + while (s[start] === s[end] && start >= 0 && end < n) { + let len = end - start + 1 + if (len > max) { + max = len + begin = start + } + start-- + end++ + } + } + + for (let mid = 0; mid < n; mid++) { + spread(mid, mid) + spread(mid, mid + 1) + } + + return s.substr(begin, max) +} + +console.log(longestPalindrome("babad")) diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\351\207\215\345\244\215\345\255\220\346\225\260\347\273\204-718.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\351\207\215\345\244\215\345\255\220\346\225\260\347\273\204-718.js" new file mode 100644 index 0000000..a4dfc61 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\346\234\200\351\225\277\351\207\215\345\244\215\345\255\220\346\225\260\347\273\204-718.js" @@ -0,0 +1,33 @@ +/** + * @param {number[]} A + * @param {number[]} B + * @return {number} + */ +let findLength = function (A, B) { + let dp = [] + let al = A.length + let bl = B.length + + for (let i = 0; i <= al; i++) { + dp[i] = [] + for (let j = 0; j <= bl; j++) { + dp[i][j] = 0 + } + } + + let max = 0 + for (let i = al - 1; i >= 0; i--) { + for (let j = bl - 1; j >= 0; j--) { + let a = A[i] + let b = B[j] + + if (a === b) { + dp[i][j] = dp[i + 1][j + 1] + 1 + max = Math.max(max, dp[i][j]) + } else { + dp[i][j] = 0 + } + } + } + return max +} diff --git "a/\345\212\250\346\200\201\350\247\204\345\210\222/\347\233\256\346\240\207\345\222\214-494.js" "b/\345\212\250\346\200\201\350\247\204\345\210\222/\347\233\256\346\240\207\345\222\214-494.js" new file mode 100644 index 0000000..d0b0687 --- /dev/null +++ "b/\345\212\250\346\200\201\350\247\204\345\210\222/\347\233\256\346\240\207\345\222\214-494.js" @@ -0,0 +1,39 @@ +/** + * @param {number[]} nums + * @param {number} S + * @return {number} + */ +let findTargetSumWays = function (nums, S) { + let ns = nums.length + if (!ns) { + return 0 + } + let min = nums.reduce((sum, cur) => sum - cur, 0) + let max = nums.reduce((sum, cur) => sum + cur, 0) + + let dp = [] + for (let n = 0; n < ns; n++) { + dp[n] = [] + } + + // 基础状态 + for (let s = min; s <= max; s++) { + let num = nums[0] + let pickPositive = s === num ? 1 : 0 + // 选负数形态 + let pickNegative = -s === num ? 1 : 0 + dp[0][s] = pickPositive + pickNegative + } + + for (let n = 1; n < ns; n++) { + for (let s = min; s <= max; s++) { + let num = nums[n] + // 选正数形态 + let pickPositive = dp[n - 1][s - num] || 0 + // 选负数形态 + let pickNegative = dp[n - 1][s + num] || 0 + dp[n][s] = pickNegative + pickPositive + } + } + return dp[ns - 1][S] || 0 +} diff --git "a/\345\217\214\346\214\207\351\222\210/\346\220\234\347\264\242\344\272\214\347\273\264\347\237\251\351\230\265 II-240.js" "b/\345\217\214\346\214\207\351\222\210/\346\220\234\347\264\242\344\272\214\347\273\264\347\237\251\351\230\265 II-240.js" new file mode 100644 index 0000000..54f7a34 --- /dev/null +++ "b/\345\217\214\346\214\207\351\222\210/\346\220\234\347\264\242\344\272\214\347\273\264\347\237\251\351\230\265 II-240.js" @@ -0,0 +1,24 @@ +/** + * @param {number[][]} matrix + * @param {number} target + * @return {boolean} + */ +let searchMatrix = function (matrix, target) { + let y = matrix.length + if (!y) return false + let x = matrix[0].length + + let row = y - 1 + let column = 0 + while (row >= 0 && column < x) { + let val = matrix[row][column] + if (val > target) { + row-- + } else if (val < target) { + column++ + } else if (val === target) { + return true + } + } + return false +}; \ No newline at end of file diff --git "a/\345\217\214\346\214\207\351\222\210/\346\234\200\346\216\245\350\277\221\347\232\204\344\270\211\346\225\260\344\271\213\345\222\214-16.js" "b/\345\217\214\346\214\207\351\222\210/\346\234\200\346\216\245\350\277\221\347\232\204\344\270\211\346\225\260\344\271\213\345\222\214-16.js" new file mode 100644 index 0000000..70d7631 --- /dev/null +++ "b/\345\217\214\346\214\207\351\222\210/\346\234\200\346\216\245\350\277\221\347\232\204\344\270\211\346\225\260\344\271\213\345\222\214-16.js" @@ -0,0 +1,49 @@ +/** + * @param {number[]} nums + * @param {number} target + * @return {number} + */ +let threeSumClosest = function (nums, target) { + let n = nums.length + if (n === 3) { + return getSum(nums) + } + // 先升序排序 此为解题的前置条件 + nums.sort((a, b) => a - b) + + let min = Infinity // 和 target 的最小差 + let res + + // 从左往右依次尝试定一个基础指针 右边至少再保留两位 否则无法凑成3个 + for (let i = 0; i <= nums.length - 3; i++) { + let basic = nums[i] + let left = i + 1 // 左指针先从 i 右侧的第一位开始尝试 + let right = n - 1 // 右指针先从数组最后一项开始尝试 + + while (left < right) { + let sum = basic + nums[left] + nums[right] // 三数求和 + // 更新最小差 + let diff = Math.abs(sum - target) + if (diff < min) { + min = diff + res = sum + } + if (sum < target) { + // 求出的和如果小于目标值的话 可以尝试把左指针右移 扩大值 + left++ + } else if (sum > target) { + // 反之则右指针左移 + right-- + } else { + // 相等的话 差就为0 一定是答案 + return sum + } + } + } + + return res +} + +function getSum(nums) { + return nums.reduce((total, cur) => total + cur, 0) +} diff --git "a/\345\217\214\346\214\207\351\222\210/\351\200\232\350\277\207\345\210\240\351\231\244\345\255\227\346\257\215\345\214\271\351\205\215\345\210\260\345\255\227\345\205\270\351\207\214\346\234\200\351\225\277\345\215\225\350\257\215-524.js" "b/\345\217\214\346\214\207\351\222\210/\351\200\232\350\277\207\345\210\240\351\231\244\345\255\227\346\257\215\345\214\271\351\205\215\345\210\260\345\255\227\345\205\270\351\207\214\346\234\200\351\225\277\345\215\225\350\257\215-524.js" new file mode 100644 index 0000000..1da6eb0 --- /dev/null +++ "b/\345\217\214\346\214\207\351\222\210/\351\200\232\350\277\207\345\210\240\351\231\244\345\255\227\346\257\215\345\214\271\351\205\215\345\210\260\345\255\227\345\205\270\351\207\214\346\234\200\351\225\277\345\215\225\350\257\215-524.js" @@ -0,0 +1,30 @@ +/** + * @param {string} s + * @param {string[]} d + * @return {string} + */ +let findLongestWord = function (s, d) { + let n = d.length + let points = Array(n).fill(-1) + + let find = "" + for (let i = 0; i < s.length; i++) { + let char = s[i] + for (let j = 0; j < n; j++) { + let targetChar = d[j][points[j] + 1] + if (char === targetChar) { + points[j]++ + let word = d[j] + let wl = d[j].length + if (points[j] === wl - 1) { + let fl = find.length + if (wl > fl || (wl === fl && word < find)) { + find = word + } + } + } + } + } + + return find +} \ No newline at end of file diff --git "a/\345\233\236\346\226\207\345\255\220\344\270\262-647.js" "b/\345\233\236\346\226\207\345\255\220\344\270\262-647.js" new file mode 100644 index 0000000..3a9c237 --- /dev/null +++ "b/\345\233\236\346\226\207\345\255\220\344\270\262-647.js" @@ -0,0 +1,29 @@ +/** + * @param {string} s + * @return {number} + */ +let countSubstrings = function (s) { + let n = s.length + if (n < 2) { + return n + } + + let count = 0 + + let spread = (start, end) => { + while (s[start] === s[end] && start >= 0 && end < n) { + start-- + end++ + count++ + } + } + + for (let mid = 0; mid < n; mid++) { + spread(mid, mid) + spread(mid, mid + 1) + } + + return count +} + +console.log(countSubstrings("a")) diff --git "a/\346\234\211\345\272\217\347\237\251\351\230\265\344\270\255\347\254\254K\345\260\217\347\232\204\345\205\203\347\264\240-378.js" "b/\346\234\211\345\272\217\347\237\251\351\230\265\344\270\255\347\254\254K\345\260\217\347\232\204\345\205\203\347\264\240-378.js" new file mode 100644 index 0000000..6ce08fc --- /dev/null +++ "b/\346\234\211\345\272\217\347\237\251\351\230\265\344\270\255\347\254\254K\345\260\217\347\232\204\345\205\203\347\264\240-378.js" @@ -0,0 +1,31 @@ +/** + * @param {number[][]} matrix + * @param {number} k + * @return {number} + */ +let kthSmallest = function (matrix, k) { + let maxY = matrix.length + let sorted = [] + let points = [] + for (let i = 0; i < maxY; i++) { + points[i] = 0 + } + + while (sorted.length < k) { + let min = Infinity + let minY + for (let y = 0; y < maxY; y++) { + let point = points[y] + let num = matrix[y][point] + if (num < min) { + min = num + minY = y + } + } + sorted.push(min) + // 选中最小项的x指针右移 + points[minY]++ + } + + return sorted[sorted.length - 1] +}; \ No newline at end of file diff --git "a/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\206\345\217\221\351\245\274\345\271\262-455.js" "b/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\206\345\217\221\351\245\274\345\271\262-455.js" new file mode 100644 index 0000000..8af19cb --- /dev/null +++ "b/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\206\345\217\221\351\245\274\345\271\262-455.js" @@ -0,0 +1,28 @@ +/** + * @param {number[]} g + * @param {number[]} s + * @return {number} + */ +let findContentChildren = function (g, s) { + g.sort((a, b) => a - b) + s.sort((a, b) => a - b) + + let i = 0 + let j = 0 + + let count = 0 + while (j < s.length && i < g.length) { + let need = g[i] + let cookie = s[j] + + if (cookie >= need) { + count++ + i++ + j++ + } else { + j++ + } + } + + return count +} diff --git "a/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\244\346\226\255\345\255\220\345\272\217\345\210\227-392.js" "b/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\244\346\226\255\345\255\220\345\272\217\345\210\227-392.js" new file mode 100644 index 0000000..bf9f8f1 --- /dev/null +++ "b/\350\264\252\345\277\203\347\256\227\346\263\225/\345\210\244\346\226\255\345\255\220\345\272\217\345\210\227-392.js" @@ -0,0 +1,50 @@ +/** + * @param {string} s + * @param {string} t + * @return {boolean} + */ +let isSubsequence = function (s, t) { + let i = 0 + let sl = s.length + if (!sl) { + return true + } + + for (let j = 0; j < t.length; j++) { + let target = s[i] + let cur = t[j] + if (cur === target) { + i++ + if (i === sl) { + return true + } + } + } + + return false +} +/** + * @param {string} s + * @param {string} t + * @return {boolean} + */ +let isSubsequence = function (s, t) { + let sl = s.length + if (!sl) { + return true + } + + let i = 0 + for (let j = 0; j < t.length; j++) { + let target = s[i] + let cur = t[j] + if (cur === target) { + i++ + if (i === sl) { + return true + } + } + } + + return false +} diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/N \347\232\207\345\220\216-51.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/N \347\232\207\345\220\216-51.js" new file mode 100644 index 0000000..f3d623b --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/N \347\232\207\345\220\216-51.js" @@ -0,0 +1,70 @@ +/** + * @param {number} n + * @return {string[][]} + */ +let solveNQueens = function (n) { + let res = [] + + // 已摆放皇后的的列下标 + let columns = [] + // 已摆放皇后的对角线1下标 左下 -> 右上 + // 计算某个坐标是否在这个对角线的方式是「行下标 + 列下标」是否相等 + let dia1 = [] + // 已摆放皇后的对角线2下标 左上 -> 右下 + // 计算某个坐标是否在这个对角线的方式是「行下标 - 列下标」是否相等 + let dia2 = [] + + // 尝试在一个n皇后问题中 摆放第index行内的皇后位置 + let putQueen = (rowIndex, row) => { + if (rowIndex === n) { + res.push(generateBoard(row)) + return + } + + // 尝试摆第index行的皇后 尝试[0, n-1]列 + for (let columnIndex = 0; columnIndex < n; columnIndex++) { + // 在列上不冲突 + let columnNotConflict = !columns[columnIndex] + // 在对角线1上不冲突 + let dia1NotConflict = !dia1[rowIndex + columnIndex] + // 在对角线2上不冲突 + let dia2NotConflict = !dia2[rowIndex - columnIndex] + + if (columnNotConflict && dia1NotConflict && dia2NotConflict) { + + columns[columnIndex] = true + dia1[rowIndex + columnIndex] = true + dia2[rowIndex - columnIndex] = true + + putQueen(rowIndex + 1, row.concat(columnIndex)) + + columns[columnIndex] = false + dia1[rowIndex + columnIndex] = false + dia2[rowIndex - columnIndex] = false + } + } + } + + putQueen(0, []) + + return res +} + +function generateBoard(row) { + let n = row.length + let res = [] + for(let y = 0; y < n; y++) { + let cur = '' + for (let x = 0; x < n; x++) { + if (x === row[y]) { + cur += 'Q' + }else { + cur += '.' + } + } + res.push(cur) + } + return res +} + +console.log(solveNQueens(4)) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\270\215\345\220\214\350\267\257\345\276\204 III-980.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\270\215\345\220\214\350\267\257\345\276\204 III-980.js" new file mode 100644 index 0000000..1213047 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\270\215\345\220\214\350\267\257\345\276\204 III-980.js" @@ -0,0 +1,72 @@ +/** + * @param {number[][]} grid + * @return {number} + */ +let uniquePathsIII = function (grid) { + let maxY = grid.length + if (!maxY) return 0 + let maxX = grid[0].length + + let validCellsCount = 0 + let entry + let visited = [] + for (let y = 0; y < maxY; y++) { + visited[y] = [] + for (let x = 0; x < maxX; x++) { + let val = grid[y][x] + if (val === 0) { + validCellsCount++ + } + if (val === 1) { + entry = [y, x] + } + } + } + + let isValid = (y, x) => { + return ( + y >= 0 && + y < maxY && + x >= 0 && + x < maxX && + !visited[y][x] && + grid[y][x] !== -1 + ) + } + + let dirs = [ + [-1, 0], + [1, 0], + [0, -1], + [0, 1], + ] + let res = 0 + + let dfs = (y, x, passCount) => { + let val = grid[y][x] + if (val === 2) { + if (passCount === validCellsCount) { + res++ + } + return + } else if (val === 0) { + passCount += 1 + } + + for (let [diffY, diffX] of dirs) { + let nextY = y + diffY + let nextX = x + diffX + if (isValid(nextY, nextX)) { + visited[nextY][nextX] = true + dfs(nextY, nextX, passCount) + visited[nextY][nextX] = false + } + } + } + + let [entryY, entryX] = entry + visited[entryY][entryX] = true + dfs(entryY, entryX, 0) + + return res +} diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\272\214\350\277\233\345\210\266\346\211\213\350\241\250-401.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\272\214\350\277\233\345\210\266\346\211\213\350\241\250-401.js" new file mode 100644 index 0000000..0a9ce85 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\344\272\214\350\277\233\345\210\266\346\211\213\350\241\250-401.js" @@ -0,0 +1,54 @@ +/** + * @param {number} num + * @return {string[]} + */ +let HOURS = [1, 2, 4, 8] +let MINUTES = [1, 2, 4, 8, 16, 32] + +let readBinaryWatch = function (num) { + let res = [] + + let combine = (arr, num) => { + if (num === 0) { + return [0] + } + let res = [] + let helper = (start, prevCount, prevSum) => { + if (prevCount === num) { + res.push(prevSum) + return + } + + for (let i = start; i < arr.length; i++) { + let cur = arr[i] + helper(i + 1, prevCount + 1, prevSum + cur) + } + } + helper(0, 0, 0) + return res + } + + for (let i = 0; i <= num; i++) { + let hours = combine(HOURS, i) + let minutes = combine(MINUTES, num - i) + + for (let hour of hours) { + if (hour > 11) continue + for (let minute of minutes) { + if (minute > 59) { + continue + } + res.push(`${hour}:${padLeft(minute)}`) + } + } + } + return res +} + +function padLeft(num) { + let str = num.toString() + if (str.length === 1) { + str = `0${str}` + } + return str +} \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227 II-47.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227 II-47.js" new file mode 100644 index 0000000..96278c2 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227 II-47.js" @@ -0,0 +1,39 @@ + +let uniqSymbol = 'X' + +let permuteUnique = function (nums) { + let n = nums.length + if (n === 1) { + return [nums] + } + let permuteSet = (nums) => { + let n = nums.length + if (n === 0) { + return new Set() + } + if (n === 1) { + return new Set(nums) + } + + let res = new Set() + for (let i = 0; i < n; i++) { + let use = nums[i] + if (use === undefined) { + continue + } + let rest = nums.slice(0, i).concat(nums.slice(i + 1, n)) + let restPermuteds = permuteSet(rest) + restPermuteds.forEach((restPermuted) => { + res.add(`${use}${uniqSymbol}${restPermuted}`) + }) + } + + return res + } + + let permuted = permuteSet(nums) + + return Array.from(permuted).map((val) => val.split(uniqSymbol).map(Number)) +} + +console.log(permuteUnique([-1,2,-1,2,1,-1,2,1])) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227-46.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227-46.js" new file mode 100644 index 0000000..59bc751 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\205\250\346\216\222\345\210\227-46.js" @@ -0,0 +1,24 @@ +/** + * @param {number[]} nums + * @return {number[][]} + */ +let permute = function (nums) { + let n = nums.length + if (n === 1) { + return [nums] + } + + let res = [] + for (let i = 0; i < n; i++) { + let use = nums[i] + let rest = nums.slice(0, i).concat(nums.slice(i + 1, n)) + let restPermuteds = permute(rest) + for (let restPermuted of restPermuteds) { + res.push(restPermuted.concat(use)) + } + } + + return res +} + +console.log(permute([1, 2, 3])) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\210\206\345\211\262\345\233\236\346\226\207\344\270\262-131.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\210\206\345\211\262\345\233\236\346\226\207\344\270\262-131.js" new file mode 100644 index 0000000..c973e26 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\210\206\345\211\262\345\233\236\346\226\207\344\270\262-131.js" @@ -0,0 +1,51 @@ +/** + * @param {string} s + * @return {string[][]} + */ + +let partition = function (s) { + let n = s.length + let ret = [] + let find = function (start, prev) { + // 最少分割一个字符 最多分割到末尾前一位 + for (let i = 1; i <= n; i++) { + let end = start + i + let cur = s.substring(start, end) + if (cur) { + let res = prev.concat(cur) + if (isPalindrome(cur)) { + if (end === n) { + ret.push(res) + } else { + find(start + i, res) + } + } + } + } + } + find(0, []) + return ret +} + +function isPalindrome(s) { + if (!s) { + return false + } + let i = 0 + let j = s.length - 1 + + while (i < j) { + let head = s[i] + let tail = s[j] + + if (head !== tail) { + return false + } else { + i++ + j-- + } + } + return true +} + +console.log(partition("aab")) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.Trie\347\211\210\346\234\254.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.Trie\347\211\210\346\234\254.js" new file mode 100644 index 0000000..9032686 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.Trie\347\211\210\346\234\254.js" @@ -0,0 +1,112 @@ +/** + * Initialize your data structure here. + */ +var Trie = function () { + this.root = new TrieNode() +} + +var TrieNode = function () { + this.children = new Map() + this.isEnd = false +} + +/** + * Inserts a word into the trie. + * @param {string} word + * @return {void} + */ +Trie.prototype.insert = function (word) { + let node = this.root + + for (let i = 0; i < word.length; i++) { + let { children } = node + let trieNode = children.get(word[i]) + if (!trieNode) { + trieNode = new TrieNode() + children.set(word[i], trieNode) + } + node = trieNode + + if (i === word.length - 1) { + node.isEnd = true + node.word = word + } + } +} + +let dirs = [ + [0, 1], + [0, -1], + [-1, 0], + [1, 0], +] +/** + * @param {character[][]} board + * @param {string[]} words + * @return {string[]} + */ +let findWords = function (board, words) { + let maxY = board.length + if (!maxY) return [] + let maxX = board[0].length + + let rootTrie = new Trie() + for (let word of words) { + rootTrie.insert(word) + } + + // 记录已访问过的二维下标 + let visited = [] + for (let y = 0; y < maxY; y++) { + visited[y] = [] + } + + let isValid = (x, y) => { + return x >= 0 && x < maxX && y >= 0 && y < maxY && !visited[y][x] + } + + // 返回结果 + let res = [] + + let dfs = (x, y, trie) => { + let char = board[y][x] + let children = trie.children + let nextTrie = children && children.get(char) + if (nextTrie) { + if (nextTrie.word) { + res.push(nextTrie.word) + nextTrie.word = null + } else { + visited[y][x] = true + for (let dir of dirs) { + let [offsetY, offsetX] = dir + let nextY = y + offsetY + let nextX = x + offsetX + if (isValid(nextX, nextY)) { + dfs(nextX, nextY, nextTrie) + } + } + visited[y][x] = false + } + } + } + + for (let y = 0; y < maxY; y++) { + for (let x = 0; x < maxX; x++) { + if (y === 1 && x === 0) debugger + dfs(x, y, rootTrie.root) + } + } + + return Array.from(new Set(res)) +} + +console.log( + findWords( + [ + ["a", "b"], + ["a", "a"], + ], + ["aaba"] + ) +) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.js" new file mode 100644 index 0000000..66d2f3d --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242 II-212.js" @@ -0,0 +1,87 @@ +let dirs = [ + [0, 1], + [0, -1], + [-1, 0], + [1, 0], +] +/** + * @param {character[][]} board + * @param {string[]} words + * @return {string[]} + */ +let findWords = function (board, words) { + let maxY = board.length + if (!maxY) return [] + let maxX = board[0].length + + // 记录已访问过的二维下标 + let visited = [] + for (let y = 0; y < maxY; y++) { + visited[y] = [] + } + + let isValid = (x, y) => { + return x >= 0 && x < maxX && y >= 0 && y < maxY && !visited[y][x] + } + + // 返回结果 + let res = [] + + let dfs = (x, y, word, index) => { + let char = board[y][x] + let targetChar = word[index] + if (char === targetChar) { + if (index === word.length - 1) { + res.push(word) + } else { + visited[y][x] = true + for (let dir of dirs) { + let [offsetY, offsetX] = dir + let nextY = y + offsetY + let nextX = x + offsetX + if (isValid(nextX, nextY)) { + dfs(nextX, nextY, word, index + 1) + } + } + visited[y][x] = false + } + } + } + + let prefixMap = new Map() + for (let y = 0; y < maxY; y++) { + for (let x = 0; x < maxX; x++) { + let prefix = board[y][x] + let pos = prefixMap.get(prefix) + if (!pos) { + prefixMap.set(prefix, [[y, x]]) + } else { + prefixMap.set(prefix, [...pos, [y, x]]) + } + } + } + + let find = (word) => { + let head = word[0] + let pos = prefixMap.get(head) + if (pos) { + pos.forEach(([y, x]) => { + dfs(x, y, word, 0) + }) + } + } + + words.forEach(find) + + return Array.from(new Set(res)) +} + +console.log( + findWords( + [ + ["a", "b"], + ["a", "a"], + ], + ["aba", "baa", "bab", "aaab", "aaa", "aaaa", "aaba"] + ) +) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242-79.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242-79.js" new file mode 100644 index 0000000..c9306df --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\215\225\350\257\215\346\220\234\347\264\242-79.js" @@ -0,0 +1,64 @@ +/** + * @param {character[][]} board + * @param {string} word + * @return {boolean} + */ +let directions = [[-1, 0], [1, 0], [0, -1], [0, 1]] // 左 右 上 下 + +let exist = function (board, word) { + let maxY = board.length + if (!maxY) return false + let maxX = board[0].length + + // 二维数组记录已访问过的元素 + let visited = new Array(maxY) + for (let y = 0; y < visited.length; y++) { + visited[y] = new Array(maxX) + } + + let inArea = (x, y) => { + return x >= 0 && x < maxX && y >= 0 && y < maxY + } + + let search = (startX, startY, wordIndex) => { + // 当前起始字符不匹配 直接失败 + let curCell = board[startY][startX] + let curChar = word[wordIndex] + if (curCell !== curChar) { + return false + } + + // 如果递归到最后一位字符 就直接返回最后一位字符是否匹配成功 + if (wordIndex === word.length - 1) { + return curChar === curChar + } + + // 进一步递归 先记录为已访问元素 防止递归的时候重复访问 + visited[startY][startX] = true + + for (let direction of directions) { + let [x, y] = direction + let nextX = startX + x + let nextY = startY + y + + // 需要保证未越界且未被访问过 + if (inArea(nextX, nextY) && !visited[nextY][nextX]) { + if (search(nextX, nextY, wordIndex + 1)) { + return true + } + } + } + // 重置已访问标记位 + visited[startY][startX] = false + } + + for (let y = 0; y < maxY; y++) { + for (let x = 0; x < maxX; x++) { + if (search(x, y, 0)) { + return true + } + } + } + + return false +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\222\214\344\270\272K\347\232\204\345\255\220\346\225\260\347\273\204-560.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\222\214\344\270\272K\347\232\204\345\255\220\346\225\260\347\273\204-560.js" new file mode 100644 index 0000000..25582b5 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\222\214\344\270\272K\347\232\204\345\255\220\346\225\260\347\273\204-560.js" @@ -0,0 +1,23 @@ +/** + * @param {number[]} nums + * @param {number} k + * @return {number} + */ +let subarraySum = function (nums, k) { + let n = nums.length + if (!n) { + return 0 + } + + let res = 0 + for (let i = 0; i < n; i++) { + let total = 0 + for (let j = i; j < n; j++) { + total += nums[j] + if (total === k) { + res += 1 + } + } + } + return res +}; \ No newline at end of file diff --git "a/DFS\351\227\256\351\242\230/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" similarity index 84% rename from "DFS\351\227\256\351\242\230/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" rename to "\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" index 88945e5..c1ffaa6 100644 --- "a/DFS\351\227\256\351\242\230/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\244\215\345\216\237ip\345\234\260\345\235\200-93.js" @@ -6,9 +6,9 @@ let restoreIpAddresses = function (s) { let res = [] let findPos = (start, prev, used) => { if (used === 3) { - // 点全部用光后 剩余字符的长度不能超过3 就是一个答案 let rest = s.substr(start) - // 最后一位不能为0 且长度在 (0,3] 范围内 + // 点全部用光后 剩余字符依然是一个合格的ip chunk + // 就视为一个答案 放入数组 if (isValidChunk(rest)) { res.push(prev.concat(rest).join(".")) } diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206 II-90.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206 II-90.js" new file mode 100644 index 0000000..d5eb09e --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206 II-90.js" @@ -0,0 +1,45 @@ +/** + * @param {number[]} nums + * @return {number[][]} + */ +var subsetsWithDup = function (nums) { + let n = nums.length + let res = [] + if (!n) { + return res + } + + nums.sort() + + let used = {} + + let helper = (start, prev, target) => { + if (prev.length === target) { + let key = genKey(prev) + if (!used[key]) { + res.push(prev) + used[key] = true + } + return + } + + for (let i = start; i < n; i++) { + let rest = n - i + let need = target - prev.length + if (rest < need) { + continue + } + helper(i + 1, prev.concat(nums[i]), target) + } + } + + for (let i = 1; i <= n; i++) { + helper(0, [], i) + } + + return [[], ...res] +}; + +function genKey(arr) { + return arr.join('~') +} \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206-78.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206-78.js" new file mode 100644 index 0000000..ca951d4 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\220\351\233\206-78.js" @@ -0,0 +1,32 @@ +/** + * @param {number[]} nums + * @return {number[][]} + */ +let subsets = function (nums) { + let res = [] + let n = nums.length + if (n === 0) { + return res + } + + let helper = (start, prev, targetLength) => { + if (start > n) { + return + } + if (prev.length === targetLength) { + res.push(prev) + return + } + + for (let i = start; i < n; i++) { + let cur = nums[i] + helper(i + 1, prev.concat(cur), targetLength) + } + } + + for (let j = 1; j <= nums.length; j++) { + helper(0, [], j) + } + + return [[], ...res] +} diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\345\244\247\345\260\217\345\206\231\345\205\250\346\216\222\345\210\227-784.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\345\244\247\345\260\217\345\206\231\345\205\250\346\216\222\345\210\227-784.js" new file mode 100644 index 0000000..91ba7b7 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\345\244\247\345\260\217\345\206\231\345\205\250\346\216\222\345\210\227-784.js" @@ -0,0 +1,34 @@ +/** + * @param {string} S + * @return {string[]} + */ +let letterCasePermutation = function (S) { + let res = [] + + let helper = (prev, rest) => { + if (prev.length === S.length) { + res.push(prev) + return + } + + let char = rest[0] + let word1 = prev + char + let nextRest = rest.substring(1) + + if (!isNaN(Number(char))) { + helper(word1, nextRest) + return + } else { + let upperChar = char.toUpperCase() + let char2 = upperChar === char ? char.toLowerCase() : upperChar + let word2 = prev + char2 + + helper(word1, nextRest) + helper(word2, nextRest) + } + } + + helper('', S) + + return res +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\350\277\255\344\273\243\347\273\204\345\220\210\345\231\250-1286.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\350\277\255\344\273\243\347\273\204\345\220\210\345\231\250-1286.js" new file mode 100644 index 0000000..709bae1 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\345\255\227\346\257\215\350\277\255\344\273\243\347\273\204\345\220\210\345\231\250-1286.js" @@ -0,0 +1,52 @@ +/** + * @param {string} characters + * @param {number} combinationLength + */ +let CombinationIterator = function (characters, combinationLength) { + let cl = characters.length + let res = [] + let helper = (start, prev) => { + let pl = prev.length + for (let i = start; i < cl; i++) { + let rest = cl - i + let diff = combinationLength - pl + if (diff > rest) { + return + } + let next = prev + characters[i] + if (next.length == combinationLength) { + res.push(next) + } else { + helper(i + 1, next) + } + } + } + helper(0, "") + this.res = res.sort((a, b) => (a > b ? 1 : -1)) + this.point = 0 +} + +/** + * @return {string} + */ +CombinationIterator.prototype.next = function () { + if (!this.hasNext()) { + return undefined + } + let val = this.res[this.point++] + return val +} + +/** + * @return {boolean} + */ +CombinationIterator.prototype.hasNext = function () { + return this.point !== this.res.length +} + +/** + * Your CombinationIterator object will be instantiated and called as such: + * var obj = new CombinationIterator(characters, combinationLength) + * var param_1 = obj.next() + * var param_2 = obj.hasNext() + */ diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\213\254\345\217\267-\351\235\242\350\257\225\351\242\230 08.09.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\213\254\345\217\267-\351\235\242\350\257\225\351\242\230 08.09.js" new file mode 100644 index 0000000..604f5c4 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\213\254\345\217\267-\351\235\242\350\257\225\351\242\230 08.09.js" @@ -0,0 +1,23 @@ +/** + * @param {number} n + * @return {string[]} + */ +let generateParenthesis = function (n) { + let res = [] + + let helper = (left, right, prev) => { + if (left < 0 || right < 0 || right < left) { + return + } + if (left === 0 && right === 0) { + res.push(prev) + return + } + + helper(left - 1, right, prev + "(") + helper(left, right - 1, prev + ")") + } + + helper(n, n, '') + return res +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\264\273\345\255\227\345\215\260\345\210\267-1079.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\264\273\345\255\227\345\215\260\345\210\267-1079.js" new file mode 100644 index 0000000..40ff332 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\346\264\273\345\255\227\345\215\260\345\210\267-1079.js" @@ -0,0 +1,23 @@ +/** + * @param {string} tiles + * @return {number} + */ +let numTilePossibilities = function (tiles) { + let res = new Set() + + let helper = (prev, rest) => { + if (prev.length > 0) { + res.add(prev) + } + + for (let i = 0; i < rest.length; i++) { + let char = rest[i] + let cur = prev + char + helper(cur, rest.substring(0, i) + rest.substring(i + 1)) + } + } + + helper('', tiles) + + return res.size +}; \ No newline at end of file diff --git "a/DFS\351\227\256\351\242\230/\347\224\265\350\257\235\345\217\267\347\240\201\347\232\204\345\255\227\346\257\215\347\273\204\345\220\210-17.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\224\265\350\257\235\345\217\267\347\240\201\347\232\204\345\255\227\346\257\215\347\273\204\345\220\210-17.js" similarity index 100% rename from "DFS\351\227\256\351\242\230/\347\224\265\350\257\235\345\217\267\347\240\201\347\232\204\345\255\227\346\257\215\347\273\204\345\220\210-17.js" rename to "\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\224\265\350\257\235\345\217\267\347\240\201\347\232\204\345\255\227\346\257\215\347\273\204\345\220\210-17.js" diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\237\251\351\230\265\347\275\256\351\233\266-73.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\237\251\351\230\265\347\275\256\351\233\266-73.js" new file mode 100644 index 0000000..fff9854 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\237\251\351\230\265\347\275\256\351\233\266-73.js" @@ -0,0 +1,37 @@ +/** + * @param {number[][]} matrix + * @return {void} Do not return anything, modify matrix in-place instead. + */ +let setZeroes = function (matrix) { + let maxY = matrix.length + if (!maxY) return + let maxX = matrix[0].length + + let handledRows = [] + let handledColumns = [] + + let zeros = [] + for (let y = 0; y < maxY; y++) { + for (let x = 0; x < maxX; x++) { + let val = matrix[y][x] + if (val === 0) { + zeros.push([y, x]) + } + } + } + + for (let [y, x] of zeros) { + if (!handledRows[x]) { + for (let i = 0; i < maxY; i++) { + matrix[i][x] = 0 + } + handledRows[x] = true + } + if (!handledColumns[y]) { + for (let i = 0; i < maxX; i++) { + matrix[y][i] = 0 + } + handledColumns[y] = true + } + } +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210-77.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210-77.js" new file mode 100644 index 0000000..8f3ccf1 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210-77.js" @@ -0,0 +1,33 @@ +/** + * @param {number} n + * @param {number} k + * @return {number[][]} + */ +let combine = function (n, k) { + let ret = [] + + let helper = (start, prev) => { + let len = prev.length + if (len === k) { + ret.push(prev) + return + } + + if (start > n) { + return + } + + // 还有 rest 个位置待填补 + let rest = k - prev.length + for (let i = start; i <= n; i++) { + if (n - i + 1 < rest) { + continue + } + helper(i + 1, prev.concat(i)) + } + } + helper(1, []) + return ret +} + +console.log(combine(4, 2)) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-39.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-39.js" new file mode 100644 index 0000000..f55dc03 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-39.js" @@ -0,0 +1,32 @@ +/** + * @param {number[]} candidates + * @param {number} target + * @return {number[][]} + */ +let combinationSum = function (candidates, target) { + let res = [] + + let helper = (start, prevSum, prevArr) => { + // 由于全是正整数 所以一旦和大于目标值了 直接结束本次递归即可。 + if (prevSum > target) { + return + } + // 目标值达成 + if (prevSum === target) { + res.push(prevArr) + return + } + + for (let i = start; i < candidates.length; i++) { + // 这里还是继续从start本身开始 因为多个重复值是允许的 + let cur = candidates[i] + let sum = prevSum + cur + let arr = prevArr.concat(cur) + helper(i, sum, arr) + } + } + + helper(0, 0, []) + + return res +} \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-40.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-40.js" new file mode 100644 index 0000000..84a3750 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\347\273\204\345\220\210\346\200\273\345\222\214-40.js" @@ -0,0 +1,47 @@ +let genKey = (arr) => arr.join("~") +/** + * @param {number[]} candidates + * @param {number} target + * @return {number[][]} + */ +let combinationSum2 = function (candidates, target) { + let res = [] + + if (!candidates.length) { + return res + } + + candidates.sort() + + let used = {} + + let helper = (start, prevSum, prevArr) => { + // 由于全是正整数 所以一旦和大于目标值了 直接结束本次递归即可。 + if (prevSum > target) { + return + } + // 目标值达成 + if (prevSum === target) { + let key = genKey(prevArr) + if (!used[key]) { + res.push(prevArr) + used[key] = true + } + return + } + + for (let i = start; i < candidates.length; i++) { + // 这里还是继续从start本身开始 因为多个重复值是允许的 + let cur = candidates[i] + let sum = prevSum + cur + let arr = prevArr.concat(cur) + helper(i + 1, sum, arr) + } + } + + helper(0, 0, []) + + return res +} + +console.log(combinationSum2([2, 1, 2, 1, 3], 6)) diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\236\272\346\227\213\347\237\251\351\230\265-54.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\236\272\346\227\213\347\237\251\351\230\265-54.js" new file mode 100644 index 0000000..5b64a29 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\236\272\346\227\213\347\237\251\351\230\265-54.js" @@ -0,0 +1,56 @@ +/** + * @param {number[][]} matrix + * @return {number[]} + */ +let spiralOrder = function (matrix) { + let maxY = matrix.length + if (!maxY) return [] + let maxX = matrix[0].length + + // 记录一个 visited 数组 + // 按照 右 -> 下 -> 左 -> 上 的方向不断前进 + // 直到遇到边界或者已经访问过的元素 则切换成下一个方向 + let dirs = [ + [0, 1], // 右 + [1, 0], // 下 + [0, -1], // 左 + [-1, 0], // 上 + ] + + let currentDirIndex = 0 + + let visited = [] + for (let y = 0; y < maxY; y++) { + visited[y] = [] + } + let isValid = (y, x) => { + return y >= 0 && y < maxY && x >= 0 && x < maxX && !visited[y][x] + } + + let targetLength = maxY * maxX + let res = [] + + let helper = (y, x) => { + let val = matrix[y][x] + res.push(val) + + if (res.length === targetLength) { + return res + } + + visited[y][x] = true + let [diffY, diffX] = dirs[currentDirIndex % 4] + let nextY = y + diffY + let nextX = x + diffX + if (!isValid(nextY, nextX)) { + [diffY, diffX] = dirs[++currentDirIndex % 4] + nextY = y + diffY + nextX = x + diffX + } + helper(nextY, nextX) + } + + helper(0, 0) + + return res +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\247\243\346\225\260\347\213\254-37.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\247\243\346\225\260\347\213\254-37.js" new file mode 100644 index 0000000..9bcf69e --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\247\243\346\225\260\347\213\254-37.js" @@ -0,0 +1,87 @@ +/** + * @param {character[][]} board + * @return {void} Do not return anything, modify board in-place instead. + */ +let solveSudoku = function (board) { + let rows = initTwoDimensionalArray(9) + let columns = initTwoDimensionalArray(9) + let grids = initTwoDimensionalArray(3) + + // 待处理下标队列 第一次扫描的时候记录下来 + let pending = [] + + for (let y = 0; y < 9; y++) { + for (let x = 0; x < 9; x++) { + let cell = board[y][x] + if (cell === ".") { + // 待填充的数独格子 记录在队列中 + pending.push([x, y]) + continue + } + // 记录下当前下标 + recordCell(x, y, cell) + } + } + + let helper = (startPendingIndex) => { + if (startPendingIndex === pending.length) { + return true + } + + let [x, y] = pending[startPendingIndex] + + for (let i = 1; i <= 9; i++) { + let cur = i.toString() + if (isValid(x, y, cur)) { + board[y][x] = cur + recordCell(x, y, cur) + if (helper(startPendingIndex + 1)) { + return true + } else { + board[y][x] = "." + restoreCell(x, y, cur) + } + } + } + } + + helper(0) + + function recordCell(x, y, cell) { + rows[y][cell] = true + columns[x][cell] = true + let [gridX, gridY] = findGridIndex(x, y) + if (!grids[gridY][gridX]) { + grids[gridY][gridX] = new Map() + } + grids[gridY][gridX].set(cell, true) + } + + function restoreCell(x, y, cell) { + rows[y][cell] = false + columns[x][cell] = false + let [gridX, gridY] = findGridIndex(x, y) + grids[gridY][gridX].set(cell, false) + } + + function isValid(x, y, cell) { + let isYConflict = rows[y][cell] + let isXConflict = columns[x][cell] + let [gridX, gridY] = findGridIndex(x, y) + let grid = grids[gridY][gridX] + let isGridConflict = grid && grid.get(cell) + return !isYConflict && !isXConflict && !isGridConflict + } +} + +function initTwoDimensionalArray(length) { + let ret = [] + for (let i = 0; i < length; i++) { + ret.push([]) + } + return ret +} + +function findGridIndex(x, y) { + return [Math.floor(x / 3), Math.floor(y / 3)] +} diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\267\263\346\260\264\346\235\277-\351\235\242\350\257\225\351\242\230 16.11.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\267\263\346\260\264\346\235\277-\351\235\242\350\257\225\351\242\230 16.11.js" new file mode 100644 index 0000000..fb26019 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\350\267\263\346\260\264\346\235\277-\351\235\242\350\257\225\351\242\230 16.11.js" @@ -0,0 +1,23 @@ +/** + * @param {number} shorter + * @param {number} longer + * @param {number} k + * @return {number[]} + */ +let divingBoard = function (shorter, longer, k) { + if (k === 0) { + return [] + } + if (shorter === longer) { + return [k * shorter] + } + + let res = [] + for (let i = 0; i <= k; i++) { + let longCount = i + let shortCount = k - i + res.push(shortCount * shorter + longCount * longer) + } + + return res +}; \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\200\222\345\275\222\347\237\251\351\230\265-59.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\200\222\345\275\222\347\237\251\351\230\265-59.js" new file mode 100644 index 0000000..0be2940 --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\200\222\345\275\222\347\237\251\351\230\265-59.js" @@ -0,0 +1,54 @@ +/** + * @param {number} n + * @return {number[][]} + */ +let generateMatrix = function (n) { + // 记录一个 visited 数组 + // 按照 右 -> 下 -> 左 -> 上 的方向不断前进 + // 直到遇到边界或者已经访问过的元素 则切换成下一个方向 + let dirs = [ + [0, 1], // 右 + [1, 0], // 下 + [0, -1], // 左 + [-1, 0], // 上 + ] + + let currentDirIndex = 0 + + let visited = [] + for (let y = 0; y < n; y++) { + visited[y] = [] + } + let isValid = (y, x) => { + return y >= 0 && y < n && x >= 0 && x < n && !visited[y][x] + } + + let targetLength = n * n + let res = [] + for (let y = 0; y < n; y++) { + res[y] = [] + } + + let helper = (y, x, num) => { + res[y][x] = num + + if (num === targetLength) { + return res + } + + visited[y][x] = true + let [diffY, diffX] = dirs[currentDirIndex % 4] + let nextY = y + diffY + let nextX = x + diffX + if (!isValid(nextY, nextX)) { + ;[diffY, diffX] = dirs[++currentDirIndex % 4] + nextY = y + diffY + nextX = x + diffX + } + helper(nextY, nextX, num + 1) + } + + helper(0, 0, 1) + + return res +} diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\241\272\346\254\241\346\225\260-1291.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\241\272\346\254\241\346\225\260-1291.js" new file mode 100644 index 0000000..13f8a5c --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\241\272\346\254\241\346\225\260-1291.js" @@ -0,0 +1,30 @@ +/** + * @param {number} low + * @param {number} high + * @return {number[]} + */ +let sequentialDigits = function (low, high) { + let lowLen = low.toString().length + let highLen = high.toString().length + let lens = [] + for (let i = lowLen; i <= highLen; i++) { + lens.push(i) + } + + let res = [] + for (let i = 0; i < lens.length; i++) { + let len = lens[i] + for (let start = 1; start <= 10 - len; start++) { + let num = start + + for (let n = start + 1; n < start + len; n++) { + num = 10 * num + n + } + if (num <= high && num >= low) { + res.push(num) + } + } + } + + return res +} \ No newline at end of file diff --git "a/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\273\204\351\207\221\347\237\277\345\267\245-1219.js" "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\273\204\351\207\221\347\237\277\345\267\245-1219.js" new file mode 100644 index 0000000..0d8d53c --- /dev/null +++ "b/\351\200\222\345\275\222\344\270\216\345\233\236\346\272\257/\351\273\204\351\207\221\347\237\277\345\267\245-1219.js" @@ -0,0 +1,69 @@ +/** + * @param {number[][]} grid + * @return {number} + */ +let getMaximumGold = function (grid) { + let maxY = grid.length + if (maxY === 0) { + return 0 + } + let maxX = grid[0].length + + let visited = [] + for (let y = 0; y < maxY; y++) { + visited[y] = [] + } + + let dirs = [ + [1, 0], + [-1, 0], + [0, -1], + [0, 1], + ] + + // 验证是否能走入这个格子 + // 1. 范围不能越界 + // 2. 本轮递归中未访问过 + // 3. 格子的值不能为 0 + let isValid = (y, x) => { + return ( + y >= 0 && + y < maxY && + x >= 0 && + x < maxX && + grid[y][x] !== 0 && + !visited[y][x] + ) + } + + let maxGold = 0 + let helper = (y, x, prevGold) => { + let val = grid[y][x] + let curGold = prevGold + val + if (curGold === 0) { + return + } + + for (let dir of dirs) { + let [diffY, diffX] = dir + let nextY = y + diffY + let nextX = x + diffX + if (isValid(nextY, nextX)) { + visited[y][x] = true + helper(nextY, nextX, curGold) + visited[y][x] = false + } else { + // 走到尽头或者不符合条件的了 + maxGold = Math.max(maxGold, curGold) + } + } + } + + for (let y = 0; y < maxY; y++) { + for (let x = 0; x < maxX; x++) { + helper(y, x, 0) + } + } + + return maxGold +} diff --git "a/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240 II-445.js" "b/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240 II-445.js" new file mode 100644 index 0000000..477c5a7 --- /dev/null +++ "b/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240 II-445.js" @@ -0,0 +1,69 @@ +var reverseList = function (head) { + if (!head) return null + let res = null + let dfs = function (node) { + if (node.next) { + dfs(node.next) + node.next.next = node + } else { + res = node + } + } + + dfs(head) + + head.next = null + + return res +}; + +var addTwoNumbers = function (l1, l2) { + l1 = reverseList(l1) + l2 = reverseList(l2) + + let i = 0 + let root = new ListNode() + let cur = root + let plus = false + + let traverse = (node1, node2) => { + let isDouble = !!node2 + while (isDouble ? (node1 && node2) : node1) { + cur.next = new ListNode() + cur = cur.next + + let sum = node1.val + (plus ? 1 : 0) + if (isDouble) { + sum += node2.val + } + + if (sum >= 10) { + sum %= 10 + plus = true + } else { + plus = false + } + cur.val = sum + + node1 = node1.next + if (isDouble) { + node2 = node2.next + } + } + + if (node1) { + traverse(node1) + } + if (node2) { + traverse(node2) + } + } + + traverse(l1, l2) + + if (plus) { + cur.next = new ListNode(1) + } + + return reverseList(root.next) +}; diff --git "a/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240-3.js" "b/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240-3.js" new file mode 100644 index 0000000..9eec915 --- /dev/null +++ "b/\351\223\276\350\241\250/\344\270\244\346\225\260\347\233\270\345\212\240-3.js" @@ -0,0 +1,59 @@ +/** + * Definition for singly-linked list. + * function ListNode(val) { + * this.val = val; + * this.next = null; + * } + */ +/** + * @param {ListNode} l1 + * @param {ListNode} l2 + * @return {ListNode} + */ +let addTwoNumbers = function (l1, l2) { + let i = 0 + let root = new ListNode() + let cur = root + let plus = false + + let traverse = (node1, node2) => { + let isDouble = !!node2 + while (isDouble ? node1 && node2 : node1) { + cur.next = new ListNode() + cur = cur.next + + let sum = node1.val + (plus ? 1 : 0) + if (isDouble) { + sum += node2.val + } + + if (sum >= 10) { + sum %= 10 + plus = true + } else { + plus = false + } + cur.val = sum + + node1 = node1.next + if (isDouble) { + node2 = node2.next + } + } + + if (node1) { + traverse(node1) + } + if (node2) { + traverse(node2) + } + } + + traverse(l1, l2) + + if (plus) { + cur.next = new ListNode(1) + } + + return root.next +} diff --git "a/\351\223\276\350\241\250/\347\247\273\351\231\244\351\223\276\350\241\250\345\205\203\347\264\240-203.js" "b/\351\223\276\350\241\250/\347\247\273\351\231\244\351\223\276\350\241\250\345\205\203\347\264\240-203.js" new file mode 100644 index 0000000..bd16019 --- /dev/null +++ "b/\351\223\276\350\241\250/\347\247\273\351\231\244\351\223\276\350\241\250\345\205\203\347\264\240-203.js" @@ -0,0 +1,18 @@ +let removeElements = function (head, val) { + let root = new ListNode() + root.next = head + let cur = root + while (cur) { + let next = cur.next + if (!next) { + break + } + let nextVal = next.val + if (nextVal === val) { + cur.next = cur.next.next + } else { + cur = cur.next + } + } + return root.next +}