[LeetCode] 3Sum Closest

Thought:
The basic pattern is just like the 3Sum.
Use a flag to store the difference between sum and the target, when we encounter a smaller difference ,we should update the difference and also update the result at the same time. 
It is a O(n^2) solution.

Code:
public class Solution {
    public int threeSumClosest(int[] num, int target) {
        int dif = Integer.MAX_VALUE;
        int result = target;
        Arrays.sort(num);
        for(int i = 0;i < num.length; i++){
            int j = i + 1;
            int k = num.length - 1;
            while(j < k){
                int sum = num[j] + num[k] + num[i];
                if(sum == target){                   
                    return target;
                }else if(sum > target){
                    k--;
                }else{
                    j++;
                }
               
                if(dif > Math.abs(sum-target)){
                    result = sum;               
                }
                dif = Math.min(dif, Math.abs(sum-target));
            }
        }
        return result;
    }
}

Second Round Code:

public class Solution {
    public int threeSumClosest(int[] num, int target) {
        int dif = Integer.MAX_VALUE;
        int result = target;
        Arrays.sort(num);
        for (int i = 0; i < num.length; i++) {
            int j = i + 1; 
            int k = num.length - 1;
            while (j < k) {
                int temp = num[i] + num[j] + num[k];
                
                if (temp == target) return target;
                if (temp < target) j++;
                else k--;

                if (dif > Math.abs(temp - target)) {
                    dif = Math.abs(temp - target);
                    result = temp;                
                }
            }
        }
        return result;
    }
}