用C语言编写一个程序，

＃i nclude<stdio.h>
＃i nclude<malloc.h>
＃i nclude<stdlib.h>
////////链表结构体////////
struct chain
{
char data;
struct chain *next;
};
////////声明////////
int Menu();
struct chain *Create(void);
struct chain *Insert(struct chain *head);
struct chain *Del(struct chain *head);
void Free(struct chain *head);
void print(struct chain *head);
////////主函数////////
void main()
{
struct chain *top;
for (; ;)
{
switch (Menu())
{
case 1:
top=Create();
print(top);
printf("\n");
break;
case 2:
top=Insert(top);
print(top);
printf("\n");
break;
case 3:
top=Del(top);
print(top);
printf("\n");
break;
case 4:
Free(top);
exit(0);
}
}
}
//