LeetCode—3sum-closest（三个数的和最近的）—java

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.

    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).

思路解析：

• 首先需要定一个位置，去找第二个和第三个，同样是low和high
• 但是需要一个变量min检查和target的差，用于返回
• 注意在找的过程中，要先排序Arrays.sort()

代码：

import java.util.*;
public class Solution {
    public int threeSumClosest(int[] num, int target) {
        if(num==null||num.length<3)
            return 0;
        Arrays.sort(num);
        int min = Integer.MAX_VALUE;
        int val =0;
        for(int i=0;i<=num.length-3;i++){
            int low = i+1;
            int high = num.length-1;
            while(low