【Leetcode】Search Insert Position

题目：

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：二分法。查找失败的话，比较当前下标位置处的值与目标值，如果目标值更大，则返回下标值加1，否则返回下标值。

代码：

class Solution {public:    int searchInsert(int A[], int n, int target) {        int mid, low=0, high=n-1;        while(low<high){            mid=(low+high)/2;            if(A[mid]==target)return mid;            if(A[mid]>target){                high=mid-1;            }else{                low=mid+1;            }        }        return target>A[low]?low+1:low;    }};