blackjack.c

#include "blackjack.h"

extern card_t *cards;
char * const suits[] = { "Spade", "Heart", "Diamond", "Club" };
char * const face[] = {
  "dummy", "A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K" };

fighter_t *new_fighter(void) {
  fighter_t * new = (fighter_t *) malloc(sizeof(fighter_t));
  new->value = 0;
  new->card = (card_t *) NULL;
  new->prev = (fighter_t *) NULL;
  return new;
}

void init_cards(void) {
  cards = (card_t *) malloc(sizeof(card_t) * DECK * 4 * 13);
  int count = 0;
  for (int i = 0; i < DECK; i++) {
    for (int j = 0; j < 4; j++) {
      for (int k = 1; k <= 13; k++) {
        cards[count].suit = suits[j];
        cards[count].face = face[k];
        cards[count].kind = k;
        if (k == 1) cards[count].worth = 11;
        else if (k < 10) cards[count].worth = k;
        else cards[count].worth = 10;
        count++;
      }
    }
  }
  shuffle();
}

void shuffle(void) {
  srand((unsigned int) time(NULL));
  for (int i = DECK * 4 * 13 - 1; i > 0; i--) {
    int random = rand() % i;
    card_t swap = cards[i];
    cards[i] = cards[random];
    cards[random] = swap;
  }
}

card_t *pull_card(void) {
  static int front = 0;
  return &cards[front++];
}

fighter_t *new_state(fighter_t *fighter, card_t *card) {
  fighter_t *new = new_fighter();
  new->prev = fighter;
  new->value = fighter->value + card->worth;
  new->card = (card_t *) malloc(sizeof(card_t));
  new->card->suit = card->suit;
  new->card->face = card->face;
  new->card->kind = card->kind;
  new->card->worth = card->worth;
  return new;
}

void print_fight_without_hole(fighter_t *dealer, fighter_t *player) {
  printf("Dealer up cards: ");
  print_up(dealer);
  puts("");
  print_player(player);
}

void print_up(fighter_t *dealer) {
  for (fighter_t *p = dealer; p->prev->prev != NULL; p = p->prev) {
    printf("%s %s", p->card->suit, p->card->face);
    if (p->prev->prev->prev != NULL) printf(", ");
  }
}

void print_player(fighter_t *player) {
  printf("Player value: %i, cards: ", player->value);
  print_hand(player);
  puts("");
}

void print_hand(fighter_t *fighter) {
  for (fighter_t *p = fighter; p->prev != NULL; p = p->prev) {
    printf("%s %s", p->card->suit, p->card->face);
    if (p->prev->prev != NULL) printf(", ");
  }
}

void print_fight(fighter_t *dealer, fighter_t *player) {
  if (dealer->value > 21) puts("Dealer Bust");
  else if (player->value > 21) puts("You Bust");
  else if (dealer->value == player->value) puts("Even");
  else if (player->value == 21) puts("You Blackjack");
  else if (dealer->value == 21) puts("Dealer Blackjack");
  else if (dealer->value > player->value) puts("You Lose");
  else if (dealer->value < player->value) puts("You Win");
  else puts("Even");
  printf("Dealer value: %i, cards: ", dealer->value);
  print_hand(dealer);
  puts("");
  print_player(player);
}

judge_t judge(fighter_t *dealer, fighter_t *player) {
  if (dealer->value == 21 && player->value == 21) return Even;
  if (dealer->value == 21) return DealerBlackjack;
  if (dealer->value < 17) return DealerDuty;
  if (dealer->value >= 17 && dealer->value < 21) return DealerPass;
  if (dealer->value > 21) return DealerBust;
  if (player->value == 21) return PlayerBlackjack;
  if (player->value > 21) return PlayerBust;
  return HitOrStay;
}

fighter_t *pull(fighter_t *fighter) {
  card_t *card = pull_card();
  return new_state(fighter, card);
}

fighter_t *try_soft_ace(fighter_t *fighter) {
  for (fighter_t *p = fighter; p->prev != NULL; p = p->prev) {
    if (p->card->kind != Ace) continue;
    p->card->kind = One;
    fighter->value -= 10;
    puts("TrySoftAce");
    return fighter;
  }
  return fighter;
}

fighter_t *hit_or_stay(fighter_t *player) {
  int n;
  char *yes_or_no = NULL;
  printf("Hit? (y/n); ");
  n = scanf("%ms", &yes_or_no);
  if (n != 1) exit(1);
  if (strcmp(yes_or_no, "y")) return player;
  return pull(player);
}

int count_ace(fighter_t *fighter) {
  int count = 0;
  for (fighter_t *p = fighter; p->prev != NULL; p = p->prev) {
    if (p->card->kind == Ace) count++;
  }
  return count;
}

int main(int ac, char **av) {
  puts("Blackjack");

  init_cards();

  fighter_t *dealer = new_fighter();
  fighter_t *player = new_fighter();

  for (int i = 0; i < 2; i++) {
    card_t *card = pull_card();
    player = new_state(player, card);
    card = pull_card();
    dealer = new_state(dealer, card);
  }

  while (1) {
    fighter_t *same = NULL;
    print_fight_without_hole(dealer, player);
    switch (judge(dealer, player)) {
    case DealerBust:
      if (count_ace(dealer) > 0) {
        dealer = try_soft_ace(dealer);
        continue;
      } // wall through
    case DealerBlackjack:
    case PlayerBlackjack:
    case Even:
      print_fight(dealer, player);
      exit(0);
      break;
    case PlayerBust:
      if (count_ace(player) > 0) {
        player = try_soft_ace(player);
        continue;
      }
      print_fight(dealer, player);
      exit(0);
      break;
    case DealerDuty:
      puts("Dealer Duty");
      dealer = pull(dealer);
      break;
    case HitOrStay:
      pull(dealer); // walk through
    case DealerPass:
      same = player;
      player = hit_or_stay(player);
      if (player != same) continue;
      print_fight(dealer, player);
      exit(0);
      break;
    default:
      break;
    }
  }
}