#include   <stdio.h>
#include   <stdlib.h>
#include   <time.h>
#define   NDEALS     3000   /* number of deals */
#define   NPLAYERS   6      /* number of players */
typedef   enum {clubs, diamonds, hearts, spades}   cdhs;
struct card {
   int    pips;
   cdhs   suit;
};
typedef   struct card   card;
card   assign_values(int pips, cdhs suit);
void   prn_card_values(card *c_ptr);
void   play_poker(card deck[52]);
void   shuffle(card deck[52]);
void   swap(card *p, card *q);
void   deal_the_cards(card deck[52], card hand[NPLAYERS][5]);
int    is_flush(card h[5]);

main()
{
   cdhs   suit;
   int    i, pips;
   card   deck[52];
   for (i = 0; i < 52; ++i) {   
      pips = i % 13 + 1;
      if (i < 13)
	 suit = clubs;
      else if (i < 26)
	 suit = diamonds;
      else if (i < 39)
	 suit = hearts;
      else
	 suit = spades;
      deck[i] = assign_values(pips, suit);
   }
   for (i = 26; i < 39; ++i)               /* print out the hearts */
      prn_card_values(&deck[i]);
   play_poker(deck);
}

card assign_values(int pips, cdhs suit)
{
   card   c;
   c.pips = pips;
   c.suit = suit;
   return c;
}

void prn_card_values(card *c_ptr)
{
   int    pips = c_ptr -> pips;
   cdhs   suit = c_ptr -> suit;
   char   *suit_name;
   if (suit == clubs) suit_name = "clubs";
   else if (suit == diamonds) suit_name = "diamonds";
   else if (suit == hearts)   suit_name = "hearts";
   else if (suit == spades)   suit_name = "spades";
   printf("card: %2d of %s\n", pips, suit_name);
}

void play_poker(card deck[52])
{
   int    i, j, flush_cnt = 0, hand_cnt = 0;
   card   hand[NPLAYERS][5];   /* each player will be dealt 5 cards */
   srand(time(NULL));           /* seed the random number generator */
   for (i = 0; i < NDEALS; ++i) {
      shuffle(deck);
      deal_the_cards(deck, hand);
      for (j = 0; j < NPLAYERS; ++j) {
	 ++hand_cnt;
	 if (is_flush(hand[j])) {
	    ++flush_cnt;
	    printf("%s%d\n%s%d\n%s%f\n\n", "      Hand number:  ", hand_cnt,
	       "     Flush number:  ", flush_cnt,
	       "Flush probability:  ", (double) flush_cnt / hand_cnt);
	 }
      }
   }
}

void shuffle(card deck[52])
{
   int   i, j;

   for (i = 0; i < 52; ++i) {
      j = rand() % 52;
      swap(&deck[i], &deck[j]);
   }
}

void swap(card *p, card *q)
{
   card   temp;

   temp = *p;
   *p = *q;
   *q = temp;
}

void deal_the_cards(card deck[52], card hand[NPLAYERS][5])
{
   int   card_cnt = 0, i, j;

   for (j = 0; j < 5; ++j)
      for (i = 0; i < NPLAYERS; ++i)
         hand[i][j] = deck[card_cnt++];
}

int is_flush(card h[5])
{
   int   i;

   for (i = 1; i < 5; ++i)
      if (h[i].suit != h[0].suit)
         return 0;
   return 1;
}