LeetCode 35.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

分析与解答：

依然是二分搜索。合理地设置边界条件，返回数组中第一个不小于target的数即可。

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