feat: 数组交集II

Author: sl1673495

两个数组的交集II-350.js

@@ -0,0 +1,36 @@
+/**
+ * @param {number[]} nums1
+ * @param {number[]} nums2
+ * @return {number[]}
+ */
+let intersect = function (nums1, nums2) {
+  let map1 = makeCountMap(nums1)
+  let map2 = makeCountMap(nums2)
+  let res = []
+  for (let num of map1.keys()) {
+    const count1 = map1.get(num)
+    const count2 = map2.get(num)
+
+    if (count2) {
+      const pushCount = Math.min(count1, count2)
+      for (let i = 0; i < pushCount; i++) {
+        res.push(num)
+      }
+    }
+  }
+  return res
+}
+
+function makeCountMap(nums) {
+  let map = new Map()
+  for (let i = 0; i < nums.length; i++) {
+    let num = nums[i]
+    let count = map.get(num)
+    if (count) {
+      map.set(num, count + 1)
+    } else {
+      map.set(num, 1)
+    }
+  }
+  return map
+}

滑动窗口/长度最小的子数组-209.js

@@ -0,0 +1,30 @@
+/**
+ * @param {number} s
+ * @param {number[]} nums
+ * @return {number}
+ */
+let minSubArrayLen = function (s, nums) {
+  let n = nums.length
+  // 定义[i,...j]滑动窗口 取这个窗口里的和
+  let i = 0
+  let j = -1
+
+  let sum = 0
+  let res = Infinity
+
+  while (i < n) {
+    if (sum < s) {
+      sum += nums[++j]
+    } else {
+      sum -= nums[i]
+      i++
+    }
+
+    if (sum >= s) {
+      res = Math.min(res, j - i + 1)
+    }
+  }
+  return res === Infinity ? 0 : res
+}
+
+console.log(minSubArrayLen(7, [2, 3, 1, 2, 4, 3]))