题解 | #牛牛的链表交换#

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

typedef struct Node{
    int data;
    struct Node* next;
}node;

node* creatlist(){
    node* headNode = (node*)malloc(sizeof(node));
    headNode->next = NULL;
    return headNode;
}

node* creatNode(int data){
    node* newNode = (node*)malloc(sizeof(node));
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}

void insertNode(node* headNode, int data){
    node* newNode = creatNode(data);

    while(headNode->next){
        headNode = headNode->next; 
    }
    headNode->next = newNode;
    newNode->next = NULL;
}

void PrintList(node* headNode){
    node* pmove = headNode->next;

    while(pmove){
        printf("%d ",pmove->data);
        pmove = pmove->next;
    }
}

void swap(node* headNode){
    node* temp;
    node* front1 = headNode->next;
    node* front2 = headNode->next->next;
    node* back1 = NULL;
    node* back2 = NULL;

    front1->next = front2->next;
    front2->next = front1;
    headNode->next = front2;

    for(temp = headNode;temp->next->next->next != NULL;temp = temp->next);
    for(back1 = headNode;back1->next->next != NULL;back1 = back1->next);
    for(back2 = headNode;back2->next != NULL;back2 = back2->next);
    
    back1->next = NULL;
    back2->next = back1;
    temp->next = back2;
}
int main() {
    int n,i;
    scanf("%d", &n);
    int array[] = {0};
    int* p = array;
    p = (int*)malloc(n*sizeof(int));
    node* list = creatlist();
    for(i = 0;i<n;i++){
        scanf("%d", p+i);
        insertNode(list, *(p+i));
    }
    swap(list);
    PrintList(list);
    return 0;
}