[数据结构与算法]反转单链表

c语言实现：

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

struct Node
{
    int data;
    struct Node* next;
}node,*p;

struct Node* init_node()
{
    struct Node *head = (struct Node*)malloc(sizeof(struct Node));
    head->next = NULL;
    return head;
}

void head_insert(int date,struct Node *head)
{
    struct Node *p1 = (struct Node*)malloc(sizeof(struct Node));
    if(p1 == NULL)
    {
        perror("malloc error");
    }
    p1->data = date;
    p1->next = head->next;
    head->next = p1;
};

//反转链表
void revert_head(struct Node* head)
{
    struct Node *pre= head;
    struct Node *cur = head->next;
    struct Node *after;
    while(cur->next != NULL )
    {
      after = cur->next;
      cur->next = pre;
     pre = cur;
     cur = after;

    }
    cur->next = pre;
    head->next->next = NULL;
    head->next = cur;

}

//打印链表
void printf_head(struct Node* head)
{
    struct Node* temp = head;
    while(temp->next != NULL)
    {
        temp = temp->next;
        printf("the date id %d\n",temp->data);

    }
}

//销毁链表
void delete_head(struct Node* head)
{
    struct Node* temp = head;
    while(temp->next != NULL)
    {
        temp = temp->next;
        printf("the date id %d\n",temp->data);
        free(temp);
    }
    free(head);
}

int main()
{


   struct Node *head = init_node();
    int num = 4;
    for(int i = 4;i > 0;i--)
    {
        head_insert(i,head);
    }
    //head_insert(num,head);
    printf_head(head);
    printf("revert \n");
    revert_head(head);
    printf_head(head);
    return 0;

}