在C中打印反向链接列表时分割错误(内核转储)

Question

我试图反转这个链接列表，但是在输入之后，它给出输出分段错误(核心转储)，同时打印列表。这只发生在我声明第4指针之前，它运行良好时，只有三个指针头部，新代码，临时。

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

int main()
    {
        struct node
        {
            int data;
            struct node *next;
        };

    struct node *head, *newnode, *temp;
    int choice = 1;

    // Creating a linked-list
    while (choice)
    {
        newnode = (struct node *)malloc(sizeof(struct node));
        printf("Enter the data: ");
        scanf("%d", &newnode->data);
        newnode->next = 0;
        if (head == 0)
        {
            head = temp = newnode;
        }
        else
        {
            temp->next = newnode;
            temp = newnode;
        }
        printf("Do you want to continue: ");
        scanf("%d", &choice);
    }
    temp = head;

    // Reversing the LL
    struct node *prevnode, *currentnode, *nextnode;
    prevnode = 0;
    currentnode = nextnode = head;
    while (nextnode != 0)
    {
        nextnode = nextnode->next;
        currentnode->next = prevnode;
        prevnode = currentnode;
        currentnode = nextnode;
    }
    head = prevnode;

    // Printing the Linked-list
    while (prevnode != 0)
    {
        printf("%d ", prevnode->data);
        prevnode = prevnode->next;
    }
    return 0;
}

据我所知，分割错误仍然无法判断到底是哪一部分造成了错误。

Answer 1

您需要将head初始化为0。默认情况下不初始化指针。否则，它就能正常工作。

Answer 2

head未初始化，因为指针在默认情况下未初始化