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35. 搜索插入位置 #71
Description
二分查找
先来看下有序数组的二分查找。
const search = function(nums, target) {
let start = 0
let end = nums.length - 1
while (start <= end) {
const mid = start + ((end - start) >> 1)
if (nums[mid] === target) return mid
if (nums[mid] < target) {
start = mid + 1
} else {
end = mid - 1
}
}
return -1
}- 题目给定一个排序数组，还有一个目标值，要直接想到用二分查找来解题
- 只不过题目增加了条件，如果找到值返回其索引，如果没有找到的话，需要返回它按顺序插入的位置 start
const searchInsert = function(nums, target) {
let start = 0
let end = nums.length - 1
while (start <= end) {
const mid = start + ((end - start) >> 1)
if (nums[mid] === target) return mid
if (nums[mid] < target) {
start = mid + 1
} else {
end = mid - 1
}
}
return start
}- 时间复杂度：O(logn)
- 空间复杂度：O(1)
Activity