[LeetCode] 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

二分搜索的修改版

class Solution {
public:
    int bsearch(int a[], int left, int right, int key)
    {
        if (left > right)
            return left;
            
        int mid = left + (right - left) / 2;
        
        if (a[mid] == key)
            return mid;
        else if (a[mid] < key)
            return bsearch(a, mid + 1, right, key);
        else
            return bsearch(a, left, mid - 1, key);
    }
    
    int searchInsert(int A[], int n, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        return bsearch(A, 0, n - 1, target);
    }
};