程序代码：

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
#define N sizeof(struct person)

struct person
{
    int num;//联系人序号
    char name[20];//联系人名字
    int phone;//联系人电话
    struct person *next;
};

void menu();//主菜单
void put(struct person *head);//输出联系人
void save(struct person *head);//存储联系人
void add(struct person *head);//添加联系人
struct person *creat(int nn);

int i,j;

void main()
{
    int aa;

    
    while(1)
    {
        printf("输入\n");
        scanf("%d",&aa);
        fflush(stdin);
        switch(aa)
        {
        case 1:    head=creat(1);
                save(head);break;

        case 2:    put(head);break;

        case 3:    add(head);
                break;
        case 0: exit(0);
        }
    }
    
}


struct person *creat(int nn)
{
    int n=0;
    int no;//记录联系人序号
    no=nn;
    struct person *head,*p1,*p2;
    p1=p2=(struct person *)malloc(N);
    p1->num=no;
    printf("输入联系人姓名:");
    gets(p1->name);
    printf("输入联系人5位号码:");
    scanf("%d",&p1->phone);
    head=NULL;
    while(p1->phone!=0)
    {
        n=n+1;
        if(n==1)head=p1;
        else p2->next=p1;
        p2=p1;
        p1=(struct person *)malloc(N);
        fflush(stdin);
        printf("输入联系人姓名:");
        gets(p1->name);
        no++;
        p1->num=no;
        printf("输入联系人5位号码:");
        scanf("%d",&p1->phone);
        
    }
    p2->next=NULL;
    
    return head;
    

}


void save(struct person *head)
{
FILE *fp;
    if((fp=fopen("PhoneBook.dat","wb"))==NULL)
    {
        printf("打开错误");
        return;
    }
    struct person *p;
    p=head;
    if(head!=NULL)
    do
    {
        if(fwrite(p,sizeof(struct person),1,fp)!=1)
        {printf("写入错误");}
        p=p->next;
    }while(p!=NULL);
    fclose(fp);
}


void put(struct person *head)
{
    FILE *fp;
    struct person *p;
    if((fp=fopen("PhoneBook.dat","rb"))==NULL)
    {
            printf("打开错误");
            return;
    }
    p=head;
        while(fread(p,sizeof(struct person),1,fp))
        {
            printf("%d\t%s\t%d\t\n",p->num,p->name,p->phone);
            p++;
        }
    fclose(fp);    
}