10.5.c

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

#define NUM_RANKS 13
#define NUM_SUITS 4
#define NUM_CARDS 5


int num_in_rank[NUM_RANKS];
int num_in_suit[NUM_SUITS];
bool straight, flush, four, three;
int pairs;   /* can be 0, 1, or 2 */

/* prototypes */
void read_cards(void);
void analyze_hand(void);
void print_result(void);

int main(void)
{
    for (;;)
        {
            read_cards();
            analyze_hand();
            print_result();
        }
}

void read_cards(void)
{
    bool card_exists[NUM_RANKS][NUM_SUITS];
    char ch, rank_ch, suit_ch;
    int rank, suit;
    bool bad_card;
    int cards_read = 0;

    for (rank = 0; rank < NUM_RANKS; rank++)
        {
            num_in_rank[rank] = 0;
            for (suit = 0; suit < NUM_SUITS; suit++)
                card_exists[rank][suit] = false;
        }

    for (suit = 0; suit < NUM_SUITS; suit++)
        num_in_suit[suit] = 0;

    while (cards_read < NUM_CARDS)
        {
            bad_card = false;

            printf("Enter a card: ");

            rank_ch = getchar();
            switch (rank_ch)
            {
                case '0':           exit(0);
                case '2':           rank = 0; break;
                case '3':           rank = 1; break;
                case '4':           rank = 2; break;
                case '5':           rank = 3; break;
                case '6':           rank = 4; break;
                case '7':           rank = 5; break;
                case '8':           rank = 6; break;
                case '9':           rank = 7; break;
                case 't': case 'T': rank = 8; break;
                case 'j': case 'J': rank = 9; break;
                case 'q': case 'Q': rank = 10; break;
                case 'k': case 'K': rank = 11; break;
                case 'a': case 'A': rank = 12; break;
                default:            bad_card = true;
            }

            suit_ch = getchar();
            switch (suit_ch)
            {
                case 'c': case 'C': suit = 0; break;
                case 'd': case 'D': suit = 1; break;
                case 'h': case 'H': suit = 2; break;
                case 's': case 'S': suit = 3; break;
                default:            bad_card = true;
            }

            while ((ch = getchar()) != '\n')
                if (ch != ' ')
                    bad_card = true;
                if (bad_card)
                    printf("Bad card; ignored.\n");
                else if (card_exists[rank][suit])
                    printf("Duplicate card; ignored.\n");
                else
                {
                    num_in_rank[rank]++;
                    num_in_suit[suit]++;
                    card_exists[rank][suit] = true;
                    cards_read++;
                }
        }
}

void analyze_hand(void)
{
    int num_consec = 0;
    int rank, suit;

    straight = false;
    flush = false;
    four = false;
    three = false;
    pairs = 0;

    /* check for flush */
    for (suit = 0; suit < NUM_SUITS; suit++)
        if (num_in_suit[suit] == NUM_CARDS)
            flush = true;

    /* check for straight */
    rank = 0;
    while (num_in_rank[rank] == 0)
        rank++;
        for (; rank < NUM_RANKS && num_in_rank[rank] > 0; rank++)
            num_consec++;
            if (num_consec == NUM_CARDS) {
                straight = true;
            return;
  }

  /* check for ace-low straight */
  if (num_consec == NUM_CARDS - 1 &&
      num_in_rank[0] > 0 && num_in_rank[NUM_RANKS-1] > 0) {
    straight = true;
    return;
  }


    /* check for 4-of-a-kind, 3-of-a-kind, and pairs */
    for (rank = 0; rank < NUM_RANKS; rank++)
        {
            if (num_in_rank[rank] == 4) four = true;
            if (num_in_rank[rank] == 3) three = true;
            if (num_in_rank[rank] == 2) pairs++;
        }
}

void print_result(void)
{
    if (straight && flush)          printf("Straight flush");
    else if (four)                  printf("Four of a kind");
    else if (three && pairs == 1)   printf("Full house");
    else if (flush)                 printf("Flush");
    else if (straight)              printf("Straight");
    else if (three)                 printf("Three of a kind");
    else if (pairs == 2)            printf("Two pairs");
    else if (pairs == 1)            printf("Pair");
    else                            printf("High card");

    printf("\n\n");
}