[leedcode 16]

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).

public class Solution { public int threeSumClosest(int[] nums, int target) { //本题是3Sum的变形，找出最接近target的值 //跟3Sum唯一的不同是，需要增加一个变量min（注意初始化值），内层每次循环时，需要与它进行比较。保留住距离target最小的值 //判断重复的逻辑可有可无，因为本题的输出只是需要返回总结果  Arrays.sort(nums); int res=0; int min=Integer.MAX_VALUE; for(int i=0;i<nums.length;i++){ int left=i+1; // if(i>0&&nums[i]==nums[i-1])continue; int right=nums.length-1; while(left<right){ int temp=nums[i]+nums[left]+nums[right];//注意局部变量的声明，为后面的循环简化表达式 if(temp==target) return res=target; if(temp>target){ if(temp-target<min){ res=temp; min=res-target; } right--; }else{ if((target-temp)<min){ res=temp; min=target-res; } left++; } } } return res; } }