prod cart

#include <iostream>
using namespace std;
char sp4[] = "";

int x4[20], n4, nrsol4 = 0, a[20];

void Afisare4() {
  int i, j;
  cout << sp4;
  for (i = 1; i <= n4; i++) cout << x4[i] << " ";
  cout << endl;
  nrsol4++;
}

void BackRec4(int k) {
  int i;
  for (i = 1; i <= a[k]; i++) {
    x4[k] = i;
    if (k == n4)
      Afisare4();
    else
      BackRec4(k + 1);
  }
}

int main() {
  int i;
  cout << endl
       << endl
       << sp4 << "Produsul cartezian a n multimi de cardinal a1, a2, ... an"
       << endl;
  cout << endl << sp4 << " Dati valoarea lui n: ";
  cin >> n4;
  cout << endl << sp4 << " Dati cardinalul fiecarei multimi: " << endl << endl;
  for (i = 1; i <= n4; i++) {
    cout << sp4 << " Multimea " << i << ": ";
    cin >> a[i];
  }
  BackRec4(1);
  cout << endl << sp4 << "Numar solutii: " << nrsol4;
  return 0;
}