程序代码：

#include <stdio.h>
#include <malloc.h>

typedef struct struct_node {
    int data;
    struct struct_node * next;
} node, * list;

int main() {
    list l = (list) malloc(sizeof(node));    // 创建头结点
    node * p = l;
    int i;
    printf("Give me the numbers you want to put into the list.\nAny none numerical character terminates the input.\n\n");
    printf("Give me a integer to append to the end of the list: ");
    fflush(stdout);
    while (scanf("%d", &i)) {                 // 创建链表
        p->next = (node *) malloc(sizeof(node));
        p = p->next;
        p->data = i;
        printf("Give me a integer to append to the end of the list: ");
        fflush(stdout);
    }
    p->next = l->next;                         // 最后一个结点的 next 指向第一个结点
    p = l->next;                               // p 指向第一个结点 
    free(l);                                   // 释放为头结点分配的空间
    l = p;                                     // l 指向第一个结点
    do {                                       // 显示循环链表中个个结点的数据
        printf("%d ", p->data);
        p = p->next;
    } while (p != l);
    return 0;
}