はじめに

以前にC言語でおみくじを作ったので今度はブラックジャックを作りました。
(追記 5/16)今回はC言語の学習のために作ったので、一部ルールを省いています。
　　　　　例えばAの判定は本当なら1または11ですが、今回は1で固定しています。
コード

# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <time.h>

typedef struct {
	char suit[8];
	int rank;
} Card;

typedef struct {
	Card hands[12];
	int handnum;
	int score;
} Participant;

void shuffle(Card deck[], int);
void drawing(Card deck[], int*, Participant*, int);
void show(Card, Participant, int);

int main(void)
{
	/* Make a deck */
	char suits[][8] = {"spade", "club", "diamond", "heart"};
	int i, j, k = 0;
	Card deck[52];

	for (i = 0; i < 4; i++) {
		for (j = 0; j < 13; j++) {
			strcpy(deck[k].suit, suits[i]);
			deck[k].rank = j + 1;
			k++;
		}
	}
	shuffle(deck, 52);
	/* end */

	/* First draw */
	Participant player;
	Participant dealer;
	int decknum = 0;
	player.handnum = 0;
	dealer.handnum = 0;
	player.score = 0;
	dealer.score = 0;

	drawing(deck, &decknum, &player, 1);
	drawing(deck, &decknum, &player, 1);
	drawing(deck, &decknum, &dealer, 1);
	drawing(deck, &decknum, &dealer, 0);
	/* end */

	/* Hit or Stand */
	char str[8];
	int choose;
	while (1) {
		do {
			printf("Choose Hit or Stand.\n");
			printf("If Hit, enter 2. If Stand, enter 1.\n");
			fgets(str, sizeof(str), stdin);
			printf("\n");
			choose = atoi(str);
		} while (!(choose == 2 || choose == 1));
		if (choose == 1) break;
		drawing(deck, &decknum, &player, 1);
		if (player.score > 21) {
			printf("You lose.\n");
			exit(0);
		}
	}
	/* end */

	/* Dealer's turn */
	show(dealer.hands[1], dealer, 1);
	while (1) {
		if (dealer.score >= 17) break;
		drawing(deck, &decknum, &dealer, 1);
	}
	/* end */

	/* Judge */
	if (dealer.score > 21 || player.score > dealer.score) {
		printf("You win!\n");
	} else if (dealer.score > player.score) {
		printf("You lose\n");
	} else {
		printf("Draw\n");
	}
	/* end */

	return 0;
}

void shuffle(Card deck[], int size)
{
	int i, j;
	Card t;

	srand((unsigned int)time(NULL));
	for (i = 0; i < size; i++) {
		j = rand() % size;
		t = deck[i];
		deck[i] = deck[j];
		deck[j] = t;
	}
}

void drawing(Card deck[], int *decknum, Participant *people, int display)
{
	Card card;
	card = deck[*decknum];
	*decknum += 1;
	people->hands[people->handnum] = card;
	people->handnum += 1;
	if (card.rank >= 11) {
		people->score += 10;
	} else {
		people->score += card.rank;
	}
	if (display) {
		show(card, *people, 0);
	}
}

void show(Card card, Participant people, int shownum)
{
	char str[32];
	if (shownum == 0) {
		strcpy(str, "Drawn card");
	} else {
		strcpy(str, "Dealer's another card");
	}
	switch (card.rank) {
                case 1:
                        printf("%s is A of %s.\n", str, card.suit);
                        break;
                case 10:
                        printf("%s is 10 of %s.\n", str, card.suit);
                        break;
                case 11:
                        printf("%s is J of %s.\n", str, card.suit);
                        break;
                case 12:
                        printf("%s is Q of %s.\n", str, card.suit);
                        break;
                case 13:
                        printf("%s is K of %s.\n", str, card.suit);
                        break;
                default:
                        printf("%s is %d of %s.\n", str, card.rank, card.suit);
                        break;
        }
        printf("The total score is %d.\n\n", people.score);
}
以上です