#include <iostream.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>


// returns a randomly chosen number between 1 and 6
int roll_die () {

  double x;

  x = rand() / (RAND_MAX + 1.0); // x is now random: 0 <= x < 1
  return 1 + ((int) (x * 6));

}


int roll_bad_die () {

  double x;

  x = rand() / (RAND_MAX + 1.0); // x is now random: 0 <= x < 1
  if (x < 0.16) return 1;
  if (x < 0.32) return 2;
  if (x < 0.52) return 3;
  if (x < 0.68) return 4;
  if (x < 0.84) return 5;
  return 6;

}


// simulates one game of Craps
// returns true if the player wins ("made the pass") and false otherwise
// sets "number_of_rolls" to the number of rolls required to produce an outcome
// set "firsat_roll_was_a_12" to true or false depending upon whether the first
// roll produced this total
bool player_made_pass (int &number_of_rolls, bool &first_roll_was_a_12) {

  int total, point;

  // simulate first roll
  total = roll_die() + roll_bad_die(); // note: 2 * roll_die() would be WRONG!!
  number_of_rolls = 1;

  // assigns a boolean value to a boolean variable...
  first_roll_was_a_12 = (total == 12);

  // see if player has scored a "natural"
  if ((total == 7) || (total == 11)) {
    return true;
  }

  // see if the player has "crapped out"
  if ((total == 2) || (total == 3) || (total == 12)) {
    return false;
  }

  // a "point" has been established
  point = total;

  // keep rolling until we repeat the point or a 7 is rolled
  for (;;) {

    total = roll_die() + roll_bad_die(); // note: 2 * roll_die() would be WRONG!!
    number_of_rolls++;

    if (total == 7) {
      return false;
    }

    if (total == point) {
      return true;
    }

  }

}


int main (void) {

  long i, pass_wins, dont_pass_wins, dont_pass_ties, total_rolls, count;
  int rolls;
  bool first_roll_was_a_12;

  for (;;) {

    cout << endl << "Enter number of games to be simulated (0 to stop): ";
    cin >> count;

    if (count <= 0) {
      return 0;
    }

    pass_wins = dont_pass_wins =dont_pass_ties = total_rolls = 0;

    for (i = 0; i < count; i++) {

      if (player_made_pass (rolls, first_roll_was_a_12)) {
        pass_wins++;
      } else {
        if (first_roll_was_a_12) {
          dont_pass_ties++;
        } else {
          dont_pass_wins++;
        }
      }
      total_rolls += rolls;

    }

    cout << endl << "A game of craps lasts an average of "
         << double(total_rolls) / count << " rolls." << endl;

    cout << "A pass bet wins "
         << (100.0 * pass_wins) / count << "% of the time." << endl;

    if (dont_pass_ties != count) { // play safe - avoid division by zero
      cout << "Ignoring ties, a don't pass bar 12 bet wins "
           << (100.0 * dont_pass_wins) / (count - dont_pass_ties)
           << "% of the time." << endl;
    } else {
      cout << "The don't pass bar 12 bet ties 100% of the time." << endl;
    }

  } // end for (;;)

}