16. 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 t) {          int result = 0;          int remainder = INT_MAX ;         sort(num.begin(), num.end());          for(int i = 0; i < num.size(); i++)              twoSum(num, i, result, remainder, t);          return result;      }      void twoSum(vector<int> num, int targetIndex, int& result, int &remainder, int t){          int i = targetIndex + 1;           int j = num.size() - 1;           while(i < j){              int thisRemainder = num[targetIndex] + num[i] + num[j] - t;              if(abs(thisRemainder) <= remainder) {                  remainder = abs(thisRemainder);                  result = num[targetIndex] + num[i] + num[j];              }              if(thisRemainder > 0) j--;               else i++;          }      }  };