从链表中删除用户选择的节点，用 c 中另一个列表中的节点替换它们

Question

我正在尝试编写一个扑克程序。现在几乎一切正常，一个问题是程序询问用户他们想要保留哪些卡片，以及他们想要丢弃哪些卡片。如果它按预期工作，用户将输入他们想要保留的卡片。没有被选中的卡片将被移除，并用牌组中的卡片替换。玩家的手牌和牌组是两个独立的链表。

这部分程序的行为有点奇怪。有时它工作正常。其他时候，它会丢弃本应保留的牌，或保留本应丢弃的牌。有时它也会改变某些牌的花色（或者可能是复制某些牌，我不确定）。

这是创建牌组的函数：

card *
createCard(int n)
{
    int i = 0;
    card *head = (card *) malloc(sizeof(card));
    card *tmp = NULL;
    card *p = NULL;

    p = head;

    for (i = 0; i < n - 1; i++) {
        tmp = (card *) malloc(sizeof(card));
        p->next = tmp;
        p = p->next;
        p->next = NULL;
    }

    tmp = head;
    for (i = 1; i <= 13; i++) {

        for (int j = 3; j <= 6; j++) {
            tmp->face = i;
            tmp->suit = j;
            tmp = tmp->next;
        }

    }

    return (head);
}

这是创建玩家手牌的函数（通过从套牌列表的前五个节点创建一个新的链表）：

void
createHand(card ** deck, card ** hand)
{
    card *tmp = NULL;
    card *card = *deck;
    int i;

//while (card != NULL)
    for (i = 0; i < 5; i++) {
        (*deck) = (*deck)->next;

        tmp = card->next;
        card->next = *hand;
        *hand = card;
        card = tmp;

    }
    (*hand)->next->next->next->next->next = NULL;
    return;

}

这是不起作用的代码部分（注意：playerHand 是玩家的手，首先是牌组）：

i = 1;

// this array keeps track of which cards the user wants to keep
int a[] = { 0, 0, 0, 0, 0 };

while (i <= 5) {
    printf("Pick cards (between 1-5) to hold (-1 to stop): ");
    scanf("%d", &keep);

    // breaks from loop if the user enters -1
    if (keep == -1)
        break;

    if (keep == 0 || keep > 5 || keep <= -2) {
        printf("Invalid index. Pick cards (between 1-5) to hold (-1 to stop): ");
        scanf("%d", &keep);
        if (keep == -1)
            break;
    }
    if (keep == -1) {
        break;
    }
    if (keep != -1) {
        // when player wants to keep a card, the corresponding index of that
        // card is set to one in the array
        a[keep - 1] = 1;
    }
    i++;
}

card *tmp;

tmp = first;
card *tmp2;

tmp2 = playerHand;
for (i = 0; i < 5; i++) {
    // if the corresponding index in the array is 0, that card is replaced
    if (a[i] == 0) {
        tmp2->face = tmp->face;
        tmp2->suit = tmp->suit;
    }
    first = first->next;
    free(tmp);
    tmp = first;
    tmp2 = tmp2->next;
}

删除这部分代码后，卡片并没有改变，所以错误一定在哪里，我只是不确定在哪里。

这是玩家选择要保留的卡片时的输出结果。在这种情况下，玩家选择保留第一张和第三张牌并丢弃其他三张：

选择卡（1-5 之间）持有（-1 停止）：1

选择卡（1-5 之间）持有（-1 停止）：3

选择卡片（1-5 之间）持有（-1 停止）：-1

Answer 1

也许代码应该是这样的？玩家如何选择替换卡？

你能展示保存卡片以供替换的代码是什么样的吗？

card *tmp;

tmp = first;
card *tmp2;

tmp2 = playerHand;
for (i = 0; i < 5; i++) {
    if (a[i] == 0) {//if the corresponding index in the array is 0, that card is replaced
        tmp2->face = tmp->face;
        tmp2->suit = tmp->suit;

        first = first->next;
        free(tmp);
        tmp = first;
    }
    tmp2 = tmp2->next;
}

用户选择要替换的卡片后，我们从牌组中取出前n张卡片。

您的代码中的错误是牌组的前五张牌总是被丢弃。如果手中的牌被标记为丢弃，则不是从牌堆中取出下一张牌，而是一张具有相同索引的牌。

card *tmp;

tmp = first;
card *tmp2;

tmp2 = playerHand;
for (i = 0; i < 5; i++) {
    // if the corresponding index in the array is 0, 
    // the card will be replaced by a card with the same index from the deck
    if (a[i] == 0) {
        tmp2->face = tmp->face;
        tmp2->suit = tmp->suit;
    }
    first = first->next; //changes the top of the deck to the next
    free(tmp);    //always removes a card from the deck
                  //so the first 5 cards will be removed
    tmp = first;  //all these three lines must be moved to the condition if

    tmp2 = tmp2->next;
}

而在while循环中，需要改代码，因为如果用户连续两次输入错误的索引，程序就会crash

    if (keep == 0 || keep > 5 || keep <= -2) {
        printf("Invalid index. ");
        continue;
    }