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

思路：使用binary search。

public class Solution {    public int searchInsert(int[] A, int target) {        if (A == null || A.length == 0) {            return -1;        }                int start = 0;        int end = A.length - 1;        int mid;        while (start + 1< end) {            mid = start + (end - start) / 2;            if (A[mid] == target) {            return mid;            } else if (A[mid] > target) {                end = mid;            } else if (A[mid] < target) {                start = mid;            }        }                if (A[start] >= target) {        return start;        } else if (A[end] >= target) {        return end;        } else {        return end + 1;        }    }}