Leetcode 刷题： 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).

public class Solution {

    public int threeSumClosest(int[] nums, int target) {

        int n= nums.length,res=0,diff=10000;;

        if(n<3) return 0;

        

        //Sort the array

        Arrays.sort(nums);

        res=nums[0]+nums[1]+nums[2];

        for(int i=0;i<n-2;i++){

            int j=i+1;

            int k=n-1;

            

            //using two pointer method 

            while(j<k){

                if(Math.abs(nums[i]+nums[j]+nums[k]-target)<Math.abs(res-target)) {

                    res=nums[i]+nums[j]+nums[k];

                }

                if (nums[i]+nums[j]+nums[k]==target) return target;

                else if(nums[i]+nums[j]+nums[k]<target)

                    j++;

                else k--;

            }

        }

        return res;

    }

}