[C语言]把一个长度为 n 的数组转换成链表并把链表前两个节点交换位置和把链表最后两个节点交换位置。

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

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

int main() {
    int n = 0;
    int i = 0;
    scanf("%d", &n);
    int arr[n];
    for (i = 0; i < n; i++){
        scanf("%d", &arr[i]);
    }

    //前两个
    Node head;
    Node *p;
    p = &head;

    for(i = 0; i < n; i++){
        if(i == 0){
            head.data = arr[i];
            head.next = NULL;
        }
        else{
            Node *New = (Node*)malloc(sizeof(Node));
            New->data = arr[i];
            New->next = NULL;
            p->next = New;
            p = p->next;
        }
    }

    //交换连接关系
    Node *top = head.next;
    p = head.next;
    head.next = p->next;
    p->next = &head;

    //后两个
    Node *last;
    Node *d;

    while (p->next->next->next != NULL) {
        p = p->next;
    }

    last = p->next->next;
    d = p->next;
    p->next = last;
    p = d;

    last->next = p;
    p->next = NULL;

    while (top != NULL) {
        printf("%d ", top->data);
        top = top->next;
    }
    return 0;
}