数据结构:单向链表系列8--反转链表

// Iterative C program to reverse a linked list
#include <stdio.h>
#include <stdlib.h>

/* Link list node */
struct Node
{
    int data;
    struct Node* next;
};

/* function to reverse the linked list */
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;
}

/* function to push a node */
void push(struct Node** head_ref, int 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;
}


/* function to print linked list */
void printList(struct Node* head)
{
    struct Node* temp = head;
    while(temp != NULL)
    {
        printf("%d ", temp->data);
        temp = temp->next;
    }
    printf("\n");
}

/* driver program to test above function */
int main() {

    /* Start with the empty list */
    struct Node* head = NULL;

    push(&head, 20);
    push(&head, 4);
    push(&head, 15);
    push(&head, 85);

    printf("Given linked list\n");
    printList(head);
    reverse(&head);
    printf("Reversed linked list\n");
    printList(head);

    return 0;
}