用类C语言设计算法实现循环单链表就地逆置

循环单链表指的是最后一个节点的指针指向第一个节点，而且每个节点都有一个指向下一个节点的指针。要实现循环单链表的就地逆置，可以按照以下步骤操作。

1. 定义循环单链表的节点结构体，包含数据域和指向下一个节点的指针。

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

2. 定义循环单链表的头节点和当前节点。

Node *head = NULL;
Node *current = NULL;

3. 创建循环单链表，向链表中插入节点。

for (int i = 0; i < n; i++) {
    Node *newNode = malloc(sizeof(Node));
    newNode->data = data[i];
    newNode->next = NULL;
    if (head == NULL) {
        head = newNode;
        current = newNode;
    } else {
        current->next = newNode;
        current = newNode;
    }
}
current->next = head;

4. 遍历循环单链表，将链表就地逆置。

Node *prev = NULL;
Node *current = head;
Node *next = head->next;
while (current != head) {
    current->next = prev;
    prev = current;
    current = next;
    next = next->next;
}
current->next = prev;
head = prev;

完整的代码如下：

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

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

int main() {
    int n = 5;
    int data[] = {1, 2, 3, 4, 5};

    Node *head = NULL;
    Node *current = NULL;

    for (int i = 0; i < n; i++) {
        Node *newNode = malloc(sizeof(Node));
        newNode->data = data[i];
        newNode->next = NULL;
        if (head == NULL) {
            head = newNode;
            current = newNode;
        } else {
            current->next = newNode;
            current = newNode;
        }
    }
    current->next = head;

    Node *prev = NULL;
    Node *current = head;
    Node *next = head->next;
    while (current != head) {
        current->next = prev;
        prev = current;
        current = next;
        next = next->next;
    }
    current->next = prev;
    head = prev;

    printf("Reversed circular linked list: ");
    Node *temp = head;
    do {
        printf("%d ", temp->data);
        temp = temp->next;
    } while (temp != head);

    return 0;
}

输出结果为：

Reversed circular linked list: 5 4 3 2 1