题解 | #牛牛的链表交换#

#include <stdio.h>
#include<stdlib.h>
#include<assert.h>
typedef struct slist
{
    int data;
    struct slist* next;
}slist;
slist* buynode(int x)
{
    slist* node=(slist*)malloc(sizeof(slist));
    assert(node);
    node->data=x;
    node->next=NULL;
    return node;
}
void pushlist(slist**pphead,int x)
{

    assert(pphead);
    slist* newnode=buynode(x);
    if(*pphead==NULL)
    {
        *pphead=newnode;
    }
    else {
    {
        slist* ptail=*pphead;
        while(ptail->next)
        {
            ptail=ptail->next;
        }
        ptail->next=newnode;
    }
    }
}
void slprint(slist* phead)
{
    slist* pcur=phead;
    while(pcur->next)
    {
        printf("%d ",pcur->data);
        pcur=pcur->next;
    }
    printf("%d ",pcur->data);
}
int main() 
{
    int n=0;
    scanf("%d",&n);
    int arr[n];
    for(int i=0;i<n;i++)
    {
        scanf("%d",&arr[i]);
    }
    int tmp=arr[0];
    arr[0]=arr[1];
    arr[1]=tmp;

    int tem=arr[n-1];
    arr[n-1]=arr[n-2];
    arr[n-2]=tem;

    slist* slist=NULL;
    for(int i=0;i<n;i++)
    {
       pushlist(&slist, arr[i]);
    }
    slprint(slist);
   return 0;
}