to_practice_c_and_cpp/pairOfSum.cpp at main · ljn7/to_practice_c_and_cpp · GitHub

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#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> pairSum(vector<int> &arr, int s){
	int i = 0, j = arr.size() - 1;
  vector<vector<int>> result;
  sort(arr.begin(), arr.end());
  while (i < j) {

    if ((arr[i] + arr[j]) == s) {

      vector<int> temp;
      temp.push_back(arr[i++]);
      temp.push_back(arr[j--]);
      result.push_back(temp);
    }

    else if ((arr[i] + arr[j]) > s)
      j--;

    else
      i++;
  }

  return result;
}

int main () {

  vector<int> vec = {2,-3,3,3,-2};


  vector<vector<int>> result = pairSum(vec, 5);

  std::vector< std::vector<int> >::const_iterator row;
  std::vector<int>::const_iterator col;

  for (row = result.begin(); row != result.end(); row++)
    for (col = row->begin(); col != row->end(); ++col)
      cout << *col << " ";


}