C 用链表排序不能正确排序

Question

我试图在上一个函数中对链接列表中的数据进行排序，但由于某种原因，它不是按所选标准排序，而是简单地将最新输入的帖子数据放在顶部并对数据进行排序，但将其分配给发错帖子了。我不知道为什么，我也不知道我在做什么。我知道代码不漂亮，我还没有机会清理它。所有其他功能均正常工作。我已经提供了运行示例。我对这个级别的编程非常陌生。有什么想法吗？

Welcome! Please make a selection to continue 1-Display the stored posts 2-Display the first post with a given attribute value 3-Display the current total number of stored posts 4-Store the data of a new post 5-Delete a post either by name or by author 6-Delete all the stored posts 7-Sort the post based on one of the following post attributes: number of likes,
number of comments, date, or post size 8-Exit

4

Add a Post Author: Bob Date of Post(YYYYMMDD): 20121205 Number of Likes: 56 Number of Comments: 23 Enter size of post: 222

Welcome! Please make a selection to continue 1-Display the stored posts 2-Display the first post with a given attribute value 3-Display the current total number of stored posts 4-Store the data of a new post 5-Delete a post either by name or by author 6-Delete all the stored posts 7-Sort the post based on one of the following post attributes: number of likes,
number of comments, date, or post size 8-Exit

4

Add a Post Author: Karen Date of Post(YYYYMMDD): 20170513 Number of Likes: 57 Number of Comments: 60 Enter size of post: 2222

Welcome! Please make a selection to continue 1-Display the stored posts 2-Display the first post with a given attribute value 3-Display the current total number of stored posts 4-Store the data of a new post 5-Delete a post either by name or by author 6-Delete all the stored posts 7-Sort the post based on one of the following post attributes: number of likes,
number of comments, date, or post size 8-Exit

7

Sort posts by: 1. Likes 2. Size 3. Date 4. Number of Comments 1

Welcome! Please make a selection to continue 1-Display the stored posts 2-Display the first post with a given attribute value 3-Display the current total number of stored posts 4-Store the data of a new post 5-Delete a post either by name or by author 6-Delete all the stored posts 7-Sort the post based on one of the following post attributes: number of likes,
number of comments, date, or post size 8-Exit

1

Author: Karen Date: 20170513 Likes: 56 Number of Comments: 60 Size: 2222

Author: Bob Date: 20121205 Likes: 57 Number of Comments: 23 Size: 222

    struct post {
    char author[50];
    int date;
    int likes;
    int comments;
    int length;
    struct post *next;
}; 

typedef struct post Post;

int menu();                 
void printList(Post *List);
void searchList(Post *List);
int numPosts(Post *List);
Post *addToList(Post *List);
void deleteAPost(Post **List);
void deleteAllPosts(Post **List);
void sort(Post **List);

int main(void) {

    int menuSelection = 0;
    Post *LIST = NULL;

    menuSelection = menu();

    while(menuSelection >= 1) {
        switch(menuSelection) {
            case 1 : printList(LIST); 
                     break;
            case 2 : searchList(LIST); 
                     break;
            case 3 : printf("Number of stored posts: %d", numPosts(LIST)); 
                     break;
            case 4 : LIST = addToList(LIST); 
                     break;
            case 5 : deleteAPost(&LIST);
                     break;
            case 6 : deleteAllPosts(&LIST); 
                     break;
            case 7 : sort(&LIST); 
                     break;
            case 8 : printf("Program terminated. Have a lovely day!\n"); exit(0);
            default: printf("Invalid!");
        }
         menuSelection = menu();
    }

    if(LIST) free(LIST);
    return 0;
}


int menu(void) {

    int menuSelection = 0;

        printf("\n***Welcome! Please make a selection to continue***\n");
        printf("1-Display the stored posts\n");
        printf("2-Display the first post with a given attribute value\n");
        printf("3-Display the current total number of stored posts\n");
        printf("4-Store the data of a new post\n");
        printf("5-Delete a post either by name or by author\n");
        printf("6-Delete all the stored posts\n");
        printf("7-Sort the post based on one of the following post attributes: number of likes, number of comments, date, or post size\n");
        printf("8-Exit\n");
        printf("\n");
        scanf("%d", &menuSelection);
        printf("\n");

    return menuSelection;
}
    void sort(Post **List){
        int choice = 0;
        printf("Sort posts by:\n1. Likes\n2. Size\n3. Date\n 4. Number of Comments\n");
        scanf(" %d",&choice);

        if (choice == 1){
            if((*List)== NULL || (*List)->next == NULL) {
               return;
            }

            Post *t1 = (*List)->next;

            while(t1 != NULL) { 
                int like = t1->likes;
                int found = 0;
                Post *t2 = *List;

                while(t2 != t1) {
                    if(t2->likes > t1->likes && found == 0) {
                        like = t2->likes;
                        t2->likes = t1->likes;
                        found = 1;
                        t2 = t2->next;
                    } else {
                        if(found == 1) {
                            int temp = like;
                            like = t2->likes;
                            t2->likes = temp;
                        }
                        t2 = t2->next;
                    }
               }
               t2->likes = like;
               t1 = t1->next;
            }
        }

Answer 1

您的排序算法修改了节点:它交换了 likes成员，但不包括结构的其余部分。正如您在输出中看到的那样，节点已损坏。

您还应该交换其他成员(next 指针除外)，或者使用不修改对象而仅更改其顺序(即仅更改 next 指针)的算法。

您应该发布结构定义以及读取、排序和写入数据的主函数，以便堆栈溢出的读者可以全面了解您的问题并找到错误和解决方案。