Solve the Global Debt Code Challeng solution

solve_the_global_debt.cpp

#include<iostream>
#include<cstring>
#include<vector>
#include<sstream>
#include<cstdlib>

using namespace std;

int main() {
  vector<string> input, countries, output;
  vector<double> results;
  string last_val;
  int i, j, k;

  cout << "Input\n";
  do {
    getline(cin, last_val);
    if(last_val != "") {
      input.push_back(last_val);
      countries.push_back(last_val.substr(0, 2));
    }
  } while(last_val != "");

  for(j = 0; j < countries.size(); j++) {
    results.push_back(0);
    for(k = 0; k < input.size(); k++) {
      if(input[k].substr(0, 2) == countries[j]) {
        results[j] += atof(input[k].substr((input[k].find(countries[j]) + 3),
                             (input[k].find(',', input[k].find(countries[j])) -
                              input[k].find(countries[j]))).c_str());
      } else {
        results[j] += atof(input[k].substr((input[k].find(countries[j], 3) + 3),
                             (input[k].find(',', input[k].find(countries[j])) -
                              input[k].find(countries[j]))).c_str());
      }
    }
  }

  for(j = 0; j < input.size(); j++) {
    for(k = 0; k < countries.size(); k++) {
      if(input[j].substr(0, 2) != countries[k]) {
        results[j] -= atof(input[j].substr((input[j].find(countries[k]) + 3),
                             (input[j].find(',', input[k].find(countries[k])) -
                              input[j].find(countries[j]))).c_str());
      }
    }
  }

  for(i = 0; i < countries.size(); i++) {
    stringstream strstream;
    strstream << countries[i] << ":" << results[i];
    output.push_back(strstream.str().c_str());
  }

  cout << "Output:\n";
  for(i = 0; i < output.size(); i++) {
    cout << output[i] << '\n';
  }

  return 0;
}