leetcode_Search Insert Position

描述：

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：

1.變形的二分查找問題

2.最後A[mid]=target，index=mid

3.最後A[mid]!=target，又分A[mid]target兩種情況，

4.if(A[mid]target),index=mid;

代碼：

public int searchInsert(int[] A, int target) {
		int len=A.length;
	    int start=0,end=len-1;
	    int mid=0;
	    int index=-1;//if A[mid]=target
	    int index2=-1;//if A[mid]!=target
	    while(start<=end)
	    {
	    	mid=(start+end)/2;
	    	if(A[mid]==target)
	    	{
	    		index=mid;
	    		break;
	    	}else if(A[mid]