LeetCode:3Sum Closest

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[] num, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
int res = Integer.MAX_VALUE;
        Arrays.sort(num);
        for(int i=0;i<num.length;i++){
            for(int j=i+1;j<num.length;j++){
                int temp = target-(num[i]+num[j]);
                int start=j+1, end=num.length-1, mid=0;
                while(start<=end){
                    mid=(start+end)/2;
                    if(num[mid]==temp){
                        break;
                    }else if(num[mid]>temp){
                        end=mid-1;
                    }else if(num[mid]<temp){
                        start=mid+1;
                    }
                }
                if(start<=end){
                    start=mid;
                    end=mid;
                }
                //while(start==i || start==j)
                   // start++;
                while(end==i || end==j)
                    end++;
                if(start<num.length)
                    res=Math.abs(num[start]-temp)<Math.abs(res-target)||res==Integer.MAX_VALUE?num[start]-temp+target:res;
                if(end>0 && end<num.length)
                    res=Math.abs(num[end]-temp)<Math.abs(res-target)||res==Integer.MAX_VALUE?num[end]-temp+target:res;
            }
        }        
        return res;
    }
}