LeetCode 35: Search Insert Position

Search Insert Position

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You may assume no duplicates in the array.

Here are few examples.
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0

解题思路

使用二分搜索（Binary Search）即可，代码如下：

class Solution {public:    int searchInsert(vector<int>& nums, int target) {        int left = 0, right = nums.size() - 1;        while (left < right) {            int middle = (left + right) >> 1;            if (nums[middle] == target) {                return middle;            }             else if (nums[middle] < target) {                left = middle + 1;            }            else {                right = middle - 1;            }        }        if (nums[left] == target){            return left;        }        else if (nums[left] > target) {            return left;        }        else {            return left + 1;        }    }};