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 

思路分析：
二分查找！代码也很简洁！

C++参考代码：

class Solution
{
public:
    int searchInsert(int A[], int n, int target)
    {
        int begin = 0;
        int end = n - 1;
        int middle = end / 2;
        while (begin <= end)
        {
            middle = (begin + end) / 2;
            if (A[middle] == target) return middle;
            else if (A[middle] < target) begin = middle + 1;
            else end = middle - 1;
        }
        return begin;//此时begin>end
    }
};

C#参考代码：

public class Solution
{
    public int SearchInsert(int[] A, int target)
    {
        int begin = 0;
        int end = A.Length - 1;
        int middle = end / 2;
        while (begin <= end)
        {
            middle = (begin + end) / 2;
            if (A[middle] == target) return middle;
            else if (A[middle] < target) begin = middle + 1;
            else end = middle - 1;
        }
        return begin;
    }
}