feat: binarySearch

Author: sl1673495

binary-search.js

@@ -0,0 +1,23 @@
+/**
+ * 二分搜索 从一个数组中搜索一个确定的数
+ */
+
+var search = function(nums, target, offset = 0) {
+  let medium = Math.floor(nums.length / 2)
+  let mediumVal = nums[medium]
+  let left = nums.slice(0, medium)
+  let right = nums.slice(medium, nums.length)
+
+  if (nums.length === 1 && mediumVal !== target) {
+    return -1
+  }
+
+  if (mediumVal > target) {
+    return search(left, target, offset)
+  } else if (mediumVal < target) {
+    return search(right, target, offset + left.length)
+  } else if (mediumVal === target) {
+    return medium + offset
+  }
+}
+console.log(search([1, 2, 3, 4, 5], 2))