35. 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

 

本题虽然是easy题目，但是通过similar problems把细节找出来，一是什么时候left<right,left<=right；而是循环内部判定条件，代码如下：

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