链表插入和反向输出

Question

我有这段代码，我正在处理添加一些字符串 aa 链接列表以反转列表。但我收到段错误错误。

segmentation fault: 11 是我在编译器上看到的。

可能会涉及内存分配问题，但目前这并不重要。

还有一个警告字符常量对于它的类型来说太长了。我不确定这意味着什么。

我怎么解决这个问题？

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

struct Node { 
    char *data[100]; 
    struct Node *next; 
}; 

static void reverse(struct Node **head_ref) { 
    struct Node *prev = NULL; 
    struct Node *current = *head_ref; 
    struct Node *next = NULL; 
    while (current != NULL) { 
        // Store next 
        next = current->next; 

        // Reverse current node's pointer 
        current->next = prev; 

        // Move pointers one position ahead. 
        prev = current; 
        current = next; 
    } 
    *head_ref = prev; 
} 

void push(struct Node **head_ref, char new_data) { 
    struct Node *new_node = (struct Node *)malloc(sizeof(struct Node)); 
    new_node->data = new_data; 
    new_node->next = (*head_ref); 
    (*head_ref) = new_node; 
} 

void printList(struct Node *head) { 
    struct Node *temp = head; 
    while (temp != NULL) { 
        printf("%s ", temp->data); 
        temp = temp->next; 
    }
}

int main() { 
    /* Start with the empty list */
    struct Node *head = NULL; 

    push(&head, "hi"); 
    push(&head, "hello");
    push(&head, "mello"); 

    printf("Given linked list\n"); 
    printList(head); 
    reverse(&head); 
    printf("\nReversed Linked list \n"); 
    printList(head); 
    getchar(); 
} 

Answer 1

在您的 push 函数中，您似乎在传递 achar当您打算传递 a 时char *。

此外，您正在new_data为同一函数中的数组赋值。

如果您将data变量更改为char *仅类型，则可以进行此分配。这意味着您之前需要根据每个字符串的大小分配必要的内存，但正如您所提到的，现在这并不重要。

这是带有这 2 个更改的代码，经过测试可以正常工作；

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


struct Node {
    char * data;
    struct Node* next;
};


static void reverse(struct Node** head_ref)
{
    struct Node* prev = NULL;
    struct Node* current = *head_ref;
    struct Node* next = NULL;
    while (current != NULL) {
        // Store next
        next = current->next;

        // Reverse current node's pointer
        current->next = prev;

        // Move pointers one position ahead.
        prev = current;
        current = next;
    }
    *head_ref = prev;
}


void push(struct Node** head_ref, char * new_data)
{
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = (*head_ref);
    (*head_ref) = new_node;
}


void printList(struct Node* head)
{
    struct Node* temp = head;
    while (temp != NULL) {
        printf("%s ", temp->data);
        temp = temp->next;
    }
}


int main(){
    /* Start with the empty list */
    struct Node* head = NULL;

    push(&head, "hi");
    push(&head, "hello");
    push(&head, "mello");


    printf("Given linked list\n");
    printList(head);
    reverse(&head);
    printf("\nReversed Linked list \n");
    printList(head);
    getchar();
}

希望这有帮助！