Leetcode #16 3Sum Closest 找3数之和最接近 解题小节

1 题目理解

昨晚上光顾着吃深夜泡面，忘了更新了。。所以这一更就算是补上昨天的，今天的另算。

这道题和 Leetcode #15 3Sum 三数之和 解题小节 很像，区别是#15是要三数之和等于目标值，这题是最接近就可以

做法其实都一样，大家可以点进去看，
也是选择一个基准，然后设立头部和尾巴，向中间靠拢

唯一的不同就是：时刻判断是否出现最接近值！

2 原题

3Sum Closest
Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

For example, given array S = {-1 2 1 -4}, and target = 1.The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

3 AC解

我是复制上一题的代码。。哈哈

public class Solution {    /**     * 其实就是直接复制上一题了     * */    public int threeSumClosest(int[] nums, int target) {        Arrays.sort(nums);        int i,j,k,result=0,reserve;        int min=Integer.MAX_VALUE;        for(i=0;i<nums.length-2;i++){            j=i+1;            k=nums.length-1;            reserve=target-nums[i];            while(j<k){                if(Math.abs(reserve-nums[j]-nums[k])<min){                    result=nums[i]+nums[j]+nums[k];                    min=Math.abs(reserve-nums[j]-nums[k]);                }                if(nums[j]+nums[k]<reserve){                        j++;                } else{                    k--;                }            }        }        return result;    }}