C 钓鱼卡转帐

我必须用c语言创建一个围棋游戏。除了交换卡片，我的大脑大部分都在工作

我已经重写了很多次了，当我在调试器中一步一步地运行它时，它是有效的，但当我运行程序时，它就不起作用了

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

struct card
{
    char suit;
    char rank;
};

struct player {
    struct hand* card_list;
    char book[7];
    size_t hand_size;
};

struct deck
{
    struct card list[52];
    int top_card;
};

struct hand
{
    struct card top;
    struct hand *next;
};

struct player user;
struct player computer;
struct deck deck_instance;

int add_card(struct player *target, struct card *new_card) {
    struct hand *end = (struct hand *) malloc(sizeof(struct hand));
    struct hand *tmp = target->card_list;
    end->top.rank = new_card->rank;
    end->top.suit = new_card->suit;
    end->next = NULL;

    if (target->card_list == NULL) {
        target->card_list = end;
        target->hand_size++;
        return 0;
    } else {
        while (tmp->next != NULL) {
            tmp = tmp->next;
        }
    }
    tmp->next = end;
    target->hand_size++;
    return 0;
}

int remove_card(struct player* target, struct card* old_card) {
    struct hand *new_hand = malloc(sizeof(struct hand));
    int new_count = 0;
    struct hand *tmp = target->card_list;
    struct hand *nextTmp = new_hand;
    while (tmp != NULL) {
        if (!(tmp->top.suit == old_card->suit && tmp->top.rank == old_card->rank)) {
            nextTmp->top.rank = tmp->top.rank;
            nextTmp->top.suit = tmp->top.suit;
            nextTmp->next = malloc(sizeof(struct hand));
            nextTmp = nextTmp->next;
            new_count++;
        }
        tmp = tmp->next;
    }
    target->card_list = new_hand;
    target->hand_size = new_count;
    return 0;
}

struct card *next_card()
{
    return &deck_instance.list[deck_instance.top_card++];
}

size_t deck_size()
{
    return 52 - deck_instance.top_card;
}

int deal_player_cards(struct player *target)
{
    if (deck_size() < 7)
    { // We don't have enough cards to deal
        return 1;
    }
    for (int i = 0; i < 7; i++)
    {
        add_card(target, next_card());
    }
    return 0;
}

int shuffle()
{
    const char *suits[4] = {"S", "H", "D", "C"};
    const char *ranks[13] = {"2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A"};
    int suit = 0;
    int rank = 0;
    for (int i = 0; i < 52; i++)
    {
        deck_instance.list[i].rank = *ranks[rank];
        rank = (rank + 1) % 13;
        deck_instance.list[i].suit = *suits[suit];
        suit = (suit + 1) % 4;
    }
    for (int i = 0; i < 1000; i++)
    {
        int j = rand() % 52;
        int k = rand() % 52;
        struct card c = deck_instance.list[j];
        deck_instance.list[j] = deck_instance.list[k];
        deck_instance.list[k] = c;
    }
    return 0;
}

void printDeck(struct player user) {
    for (int i = 0; i < user.hand_size; i++) {
        printf("%c%c ", user.card_list[i].top.rank, user.card_list[i].top.suit);
    }
    printf("\n");
}

int transfer_cards(struct player* src, struct player* dest, char rank) {
    int result = 0;
    int hand_size = src->hand_size;
    for (int i = 0; i < hand_size; i++) {
        if (src->card_list[i].top.rank == rank) {
            result++;
            add_card(dest, &src->card_list[i].top);
            remove_card(src, &src->card_list[i].top);

        }
    }
    return result;
}

int main(int args, char* argv[])
{
    printf("Shuffling deck....\n");
    shuffle();
    deal_player_cards(&user);
    deal_player_cards(&computer);
    printf("Players 1's Hand - ");
    printDeck(user);
    printf("Players 2's Hand - ");
    printDeck(computer);
    char rank = '5';
    transfer_cards(&computer, &user, rank);
    printf("Players 1's Hand - ");
    printDeck(user);
    printf("Players 2's Hand - ");
    printDeck(computer);

}

正确的输出应该是

Shuffling deck....
Players 1's Hand - JC 5H 9H AH TD 3C AS 
Players 2's Hand - 4D 5D TS QC 6H TC 5S 
Players 1's Hand - JC 5H 9H AH TD 3C AS 5D 5S 
Players 2's Hand - 4D TS QC 6H TC  

您可以调用deal\u player\u cards（）->add\u card（），然后检查target->card\u list的值。卡片列表和手牌大小未在此点初始化。在deal_player_cards（）中，您需要在调用add_card（）之前初始化播放器结构。这会导致您遇到未定义的行为

int deal_player_cards(struct player *target)
{
    target->card_list = NULL;
    target->hand_size = 0;

    if (deck_size() < 7)
    { // We don't have enough cards to deal
        return 1;
    }
    for (int i = 0; i < 7; i++)
    {
        add_card(target, next_card());
    }
    return 0;
}

---

这可能是代码中未定义行为的症状。当我运行它（MSVC）时，它会打印除了每手牌中的第一张牌以外的所有牌的垃圾：

玩家1的手-9CEI218Y

和

玩家2的手-9HÚR6DÚR5CÚRKS

和

玩家1的手-9CEI218Y m

和

玩家2的手-9H-[6D]]KS––

我使用gcc，但看不出UB就是这样使用的。使用哪种编译器，或者使用什么调试或优化选项，都不会有任何区别。好吧，我该如何处理UB？好吧，简短而没有帮助的答案是“编写定义良好的代码”。更有用的花絮包括“定义时初始化所有内容”、“清楚代码中堆分配块的概念“所有权”，以及所有者离开时的

free

”、“习惯性地检查返回代码”、“如果无法以其他方式证明它们是好的，则在使用它们之前使用空测试指针”，等等该列表应包括“自动存储中优先分配给

alloc

family functions”，除非您无法避免使用head进行此分配。不幸的是，处理的手中仍然有垃圾-每次运行都有不同的垃圾。你试过了吗？编辑建议不要。不，我没有。我刚刚向UB致词。printDeck（）至少还有一个其他问题。我把它添加到我的答案中。

int deal_player_cards(struct player *target)
{
    target->card_list = NULL;
    target->hand_size = 0;

    if (deck_size() < 7)
    { // We don't have enough cards to deal
        return 1;
    }
    for (int i = 0; i < 7; i++)
    {
        add_card(target, next_card());
    }
    return 0;
}

void printDeck(struct player user) {
    struct hand *temp_hand;

    temp_hand = user.card_list;
    while (temp_hand != NULL)
    {
        printf("%c%c ", temp_hand->top.rank, temp_hand->top.suit);
        temp_hand = temp_hand->next;
    }
    printf("\n");
}