3Sum Closest

题目描述：

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.

确定一个，然后用两指针法，代码如下：

public class Solution {    public int threeSumClosest(int[] nums, int target) {        Arrays.sort(nums);        int result=0;        int min=Integer.MAX_VALUE;        for (int i = 0; i < nums.length; i++) {            int low=i+1,high=nums.length-1;            while(low<high){                int n=Math.abs(target-nums[i]-nums[low]-nums[high]);                if(n<min){                    min=n;                    result=nums[i]+nums[low]+nums[high];                }                //System.out.println("min:"+min);                if(target-nums[i]-nums[low]-nums[high]>0){                    low++;                }else{                    high--;                }            }        }        return result;    }}