Search Insert Position

Problem:

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

    二分查找，如果存在，则返回索引，如果不存在，则返回左右指针中的较大者。

Solution:

public class Solution {
    public int searchInsert(int[] A, int target) {
        if(A==null)
             return -1;
        int l = 0, r = A.length-1,m;
        while(l<=r)
        {
             m = (l+r)/2;
             if(target>A[m])
                 l = m+1;
             else if(target<A[m])
                 r = m-1;
             else
                 return m;
        }
        return l>r?l:r;
    }
}