leetcode------Search Insert Position

题目：	Search Insert Position
通过率：	35.3%
难度：	中等

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

本题思路非常明确，就是找元素的位置，如果元素存在返回元素的位置，如果元素不存在返回元素应该插入的位置，对于这个应该插入的位置要进行细化讨论，具体看代码，

java：

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