uploaded blackjack.c

blackjack.c

@@ -0,0 +1,139 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <time.h>
+
+typedef enum {
+    CARD_ACE, CARD_2, CARD_3, CARD_4, CARD_5, CARD_6, CARD_7, CARD_8, CARD_9, CARD_10, CARD_J, CARD_Q, CARD_K, CARD_COUNT,
+} Card_Type;
+
+typedef struct {
+    Card_Type cards[16];
+    int count;
+} Hand;
+
+typedef struct {
+    Card_Type cards[64];
+    int count;
+} Deck;
+
+static void swapCard(Card_Type *a, Card_Type *b) {
+    Card_Type tmp = *a;
+    *a = *b;
+    *b = tmp;
+}
+
+void shuffleDeck(Deck *d) {
+    if (!d) return;
+    int n = d->count;
+    if (n <= 1) return;
+    for (int i = n - 1; i > 0; --i) {
+        int j = rand() % (i + 1); // uniform in [0,i]
+        swapCard(&d->cards[i], &d->cards[j]);
+    }
+}
+
+int cardValue(Card_Type card) {
+    return card + 1 <= 10 ? card + 1 : 10;
+}
+
+void takeCard(Deck *deck, Hand *hand) {
+    hand->cards[hand->count++] = deck->cards[--deck->count];
+};
+
+int countScore(Hand hand) {
+    int score = 0;
+    bool has_ace = false;
+    for(int i = 0; i < hand.count; i++){
+        if(hand.cards[i] == CARD_ACE) has_ace = true;
+        score += cardValue(hand.cards[i]);
+    }
+    return score + has_ace * 10;
+}
+
+void printResult(int player_score, int dealer_score) {
+    if(player_score > 21) {
+        puts("player lost\n");
+        return;
+    } else if(player_score == 21 && dealer_score != 21) {
+        puts("!!!BLACKJACK!!!\n");
+        return;
+    } else if(player_score == dealer_score) {
+        puts("push\n");
+        return;
+    } else if(dealer_score > 21 || player_score > dealer_score) {
+        puts("player won\n");
+        return;
+    } else if(dealer_score > player_score) {
+        puts("player lost\n");
+        return;
+    }
+}
+
+int main() {
+    srand((unsigned)time(NULL));
+    Deck deck = {0};
+    for(int i = 0; i < CARD_COUNT; i++){
+        deck.cards[deck.count++] = i;
+        deck.cards[deck.count++] = i;
+        deck.cards[deck.count++] = i;
+        deck.cards[deck.count++] = i;
+    }
+
+    shuffleDeck(&deck);
+    shuffleDeck(&deck);
+    shuffleDeck(&deck);
+
+    Hand dealer = {0};
+    Hand player = {0};
+    takeCard(&deck, &player);
+    takeCard(&deck, &player);
+    takeCard(&deck, &dealer);
+
+    char cmd;
+    bool ask = true;
+    if(countScore(player) == 21) ask = false;
+    while(ask){
+        printf("player score: %d\n", countScore(player));
+        printf("dealer score: %d\n", countScore(dealer));
+        puts("[H]it or [S]tand?\n");
+        
+        do {
+            cmd = getchar();
+            if (cmd == EOF) return 0;
+            if (cmd == '\n') break;
+        } while (cmd == ' ' || cmd == '\t');
+        if (cmd == '\n') continue;
+
+        int ch;
+        while ((ch = getchar()) != EOF && ch != '\n') { /* discard */ }
+
+        switch (cmd) {
+            case 'h':
+            case 'H':
+                takeCard(&deck, &player);
+                if(countScore(player) >= 21) ask = false;
+                break;
+            case 's':
+            case 'S':
+                ask = false;
+                break;
+            case 'q':
+                puts("Quitting.");
+                return 0;
+            default:
+                printf("Unknown command: %c\n", cmd);
+        }
+    }
+
+    if(countScore(player) >= 21) {
+        takeCard(&deck, &dealer);
+    } else {
+        while(countScore(dealer) < 17) takeCard(&deck, &dealer);
+    }
+
+    printf("player score: %d\n", countScore(player));
+    printf("dealer score: %d\n", countScore(dealer));
+    printResult(countScore(player), countScore(dealer));
+    return 0;
+}