LeetCode算法入门- Search Insert Position -day19

1. 题目描述
   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.

Example 1:

Input: [1,3,5,6], 5
Output: 2

Example 2:

Input: [1,3,5,6], 2
Output: 1

Example 3:

Input: [1,3,5,6], 7
Output: 4

Example 4:

Input: [1,3,5,6], 0
Output: 0

2. 题目分析
   利用二分法来进行查找

3. Java实现

class Solution {public int searchInsert(int[] nums, int target) {if(nums == null || nums.length == 0)return 0;int left = 0;int right = nums.length - 1;int mid = 0;while(left <= right){//二分法mid = (left + right)/2;if(nums[mid] == target){//这里是返回midreturn mid;}else if(nums[mid] > target){right = mid - 1;}else{left = mid + 1;}}//记得最后返回left而不是midreturn left;}
}