LeetCode-Java-35.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.
给一个排序好的数组，和一个target数据，如果找到目标，返回他的下标，如果没找到那么返回他应该插入的下标
You may assume no duplicates in the array.
你可以假设数组不重复
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

代码

主要运用二分的思想进行查找。

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