C - 我想反转链表

Question

我想反转链接列表，但我的代码似乎不起作用。我不知道这是怎么回事。我使用了我在这里找到的一个 reverse() 函数，我什至在纸上测试了它，所以我很确定代码是好的，但我肯定还缺少一些东西。我很想知道出了什么问题。这是我的代码:

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


typedef struct node{
    int val;
    struct node * next;
}node;

void push(int val, node **head){
    node* temp=(node*)malloc(sizeof(node));
    node* current=*head;
    temp->val=val;
    if(*head==NULL)
        {*head=temp;
        temp->next=NULL;}
    else
        {while(current->next!=NULL)
            current=current->next;
    current->next=temp;
    temp->next=NULL;}
 }
int reverse(node * head){
   node *previous = NULL;
   node *current = head;
   node *forward;
   while (current != NULL) {
       forward = current->next;
       current->next = previous;
       previous = current;
       current = forward;
      }
    return previous;

   }
 void print(node *new_head){

    node* current2=new_head;
    current2=current2->next;
    while(current2!=NULL)
     {
       printf("%d", current2->val);
       current2=current2->next;
      }}

int main()
{   node * head= NULL;
    int n;
    node * new_head;
    scanf("%d", &n);
    push(n,head);
    scanf("%d", &n);
    push(n,head);
    scanf("%d", &n);
    push(n,head);
    new_head=reverse(head);
    print(new_head);

    return 0;}

我只想反转输入，例如:1,2,3。所以输出将是 3,2,1。

Answer 1

尝试以下操作

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

typedef struct node
{
    int val;
    struct node * next;
} node;

void push( node **head, int val )
{
    node **current = head;

    while ( *current ) current = &( *current )->next;

    *current = ( node * )malloc( sizeof( node ) );

    ( *current )->val  = val;
    ( *current )->next = NULL;
}

node * reverse( node * head )
{
    node *new_head = NULL;
    node *current = head;

    while ( current ) 
    {
        node *next = current->next;
        current->next = new_head;
        new_head = current;
        current = next;
    }

    return new_head;
}

void print( const node *head )
{
    for ( ; head; head = head->next ) printf( "%d ", head->val );
    printf( "\n" );
}

void delete( node *head )
{
    while ( head )
    {
        node *tmp = head;
        head = head->next;
        free( tmp );
    }
}

int main()
{   
    node *head = NULL;
    int n;

    scanf( "%d", &n );
    push( &head, n );

    scanf( "%d", &n );
    push( &head, n );

    scanf( "%d", &n );
    push( &head, n );

    print( head );

    head = reverse( head );

    print( head );

    delete( head );

    return 0;
}

如果输入 1 2 3 输出将为

1 2 3 
3 2 1