程序代码：

#include<stdio.h>
#include<stdlib.h>
struct Node
{
char data;
struct Node *next;
};
void main()
{
struct Node *p,*q,*r;
p=(struct Node *)malloc(sizeof(struct Node));
q=(struct Node *)malloc(sizeof(struct Node));
r=(struct Node *)malloc(sizeof(struct Node));
p->data='A';p->next=q;
q->data='B';q->next=NULL;
r->data='C';r->next=NULL;
r->next=p->next;p->next=r;
while(p!=NULL)
{
printf("%c",p->data);
p=p->next;
}
printf("\n");
}