#include<iostream>
#include <string>
#include<assert.h>

using namespace std;

void swap(string & v, int i, int j) { char tmp=v[i]; v[i]=v[j]; v[j]=tmp; }

void listPermutations(string & vect, int n_fixed) {
  // lista tutte le stringhe ottenibili da vect permutandone
  // i simboli dall' (n_fixed)-esimo in poi.
  // (Ossia tenendo fissi i primi n_fixed simboli).
  assert( n_fixed >= 0 );
  if ( n_fixed >= vect.length() -1 )  cout << vect << endl;
  else
    for(int j = n_fixed; j< vect.length(); j++) {
      swap(vect, n_fixed, j);
      listPermutations(vect, n_fixed +1);
      swap(vect, n_fixed, j);
    }
}

int main() {
  string vect = "ABCDE"; // My test: cout << vect[0] << endl;
  cout << "We will list all permutations of the " << vect.length() << " symbols in the string " << vect << ":" << endl;
  listPermutations(vect, 0);
}