leetcode 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).

class Solution {public:    int threeSumClosest(vector<int> &num, int target) {         sort(num.begin(), num.end());        int min =100000, distance = 1000000;        for(size_t i = 0; i < num.size(); i++)        {            int j = i+1;            int k = num.size() - 1;            while(j < k)            {                if(num[i] + num[j] + num[k] < target)                {                    if(abs(num[i] + num[j] + num[k] - target) < distance){                        min = num[i] + num[j] + num[k];distance = abs(min - target);}                    j++;                }                else if(num[i] + num[j] + num[k] > target)                {                    if(abs(num[i] + num[j] + num[k] - target) < distance){                     min = num[i] + num[j] + num[k]; distance = abs(min - target);}                        k--;                }                else                {                    return  target;                }            }        }        return min;    }};