test BruteForce

// Artem Korshenko
// cppstudio.com/post/8059
// Linux C++11
#include <iostream>
#include <cmath> // pow() - function

std::string input ( std::string str ) {
  std::cout << str;
  std::getline ( std::cin, str );
  return str;
  } // Python style


int main() {
  std::string str_password;
  do {
    str_password = input ( "Enter password: " );

    if ( str_password.size() < 1 ) std::cout << "Please, enter password" << std::endl;
    } while ( str_password.size() < 1 );

  std::string str_chars;
  do {
    std::cout << "Type '+' to include... or press 'Enter' to skip" << std::endl;
    if ( input ( "Small chars: " ) == "+" ) str_chars += "qwertyuiopasdfghjklzxcvbnm";
    if ( input ( "Large chars: " ) == "+" ) str_chars += "QWERTYUIOPASDFGHJKLZXCVBNM";
    if ( input ( "Digits: "      ) == "+" ) str_chars += "0123456789";
    if ( input ( "Symbols: "     ) == "+" ) str_chars += " `~!@#$%^&*()_+=-][}{\';|:/.,<>?\\\"";

    if ( str_chars.size() < 1 ) std::cout << "Please, select characters" << std::endl;
    } while ( str_chars.size() < 1 );

  bool cycle = true;
  bool founded = false;
  int size_password = str_password.size();
  int size_chars    = str_chars.size();
  int indexer[ size_password ];
  std::string str_bruteforce;
  str_bruteforce.resize ( size_password );
  for ( int i = 0; i < size_password; ++i ) indexer[i] = 0;

  std::cout << "Selected characters: " << str_chars << std::endl;
  std::cout << "Lenght of password: " << size_password << std::endl;
  std::cout << "Length of dictionary: " <<  size_chars << std::endl;
  std::cout << "Number of variants password: " << ulong ( std::pow ( size_chars, size_password ) ) << std::endl; // variants = library ^ password
  std::cout << "Please wait..." << std::endl;

  while ( true ) {
    for ( int i = size_password - 1; i >= 0; --i ) {
      if ( i != 0 ) {
        if ( indexer[i] == size_chars ) {
          indexer[i] = 0;
          indexer[i - 1]++;
          }
        }
      }

    for ( int i = 0; i < size_password; ++i ) str_bruteforce[i] = str_chars[indexer[i]];

    cycle = true;
    if ( str_bruteforce == str_password ) {
      std::cout << "You password: " << str_bruteforce << std::endl;
      cycle = false;
      founded = true;
      } if ( !cycle ) break;

    cycle = false;
    for ( int i = 0; i < size_password; ++i ) {
      if ( indexer[i] != size_chars - 1 ) {
        cycle = true;
        break;
        }
      } if ( !cycle ) break;

    indexer[ size_password - 1 ]++;
    }
  if ( !founded ) std::cout << "Error selected characters" << std::endl;
  }