关于C语言通讯录的代码,大家来看看
#include <stdio.h>
//#include <malloc.h> //得到指向大小为Size的内存区域的首字节的指针//
#include <string.h>
#include <stdlib.h> //标准库函数//
#define NULL 0
#define LEN sizeof(struct address_list) //计算字节//
int n;
struct address_list
{
char name[30]; //名字
char work[30]; //职业
char handset[30]; //手机
char email[30]; //电子邮件
char address[30]; //通讯地址
struct address_list *next;
};
struct address_list *shifang(struct address_list *head); // 释放内存函数声明
//创建函数,不带头结点的链表
struct address_list *creat(void)
{
struct address_list *head,*p1,*p2;
char name[20];
n=0;
p1=(struct address_list *)malloc(LEN);
p2=p1; //强制内存转换
printf("请输入通讯录的内容!\n姓名输入为0时表示创建完毕!\n");
printf("请输入姓名:");
gets(name);
if(strcmp(name,"0")!=0)
{
strcpy(p1->name,name);
printf("请输入职业:"); gets(p1->work);
printf("请输入手机:"); gets(p1->handset);
printf("请输入电子邮件:"); gets(p1->email);
printf("请输入通讯地址:"); gets(p1->address);
head=NULL;
while(1)
{
n=n+1; //记录通讯录人数个数
if(n==1) ///????n==0
head=p1;
else
p2->next=p1;
p2=p1;
printf("请输入姓名:");
gets(name);
if(strcmp(name,"0")==0)
{
break;
}
else
{
p1=(struct address_list *)malloc(LEN);
strcpy(p1->name,name);
printf("请输入职业:"); gets(p1->work);
printf("请输入手机:"); gets(p1->handset);
printf("请输入电子邮件:"); gets(p1->email);
printf("请输入通讯地址:"); gets(p1->address);
}
}
p2->next=NULL;
return head;
}
else
return 0;
}
//输出函数
void print(struct address_list *head)
{
struct address_list *p;
if(head!=NULL)
{
p=head;
printf("本通讯录现在共有%d人:\n",n);
printf("---姓名-------职业--------手机-------Email-------通讯地址\n");
printf("==================================\n");
do
{
printf("== %s",p->name); printf(" ");
printf("%s",p->work); printf(" ");
printf("%s",p->handset); printf(" ");
printf("%s",p->email); printf(" ");
printf("%s",p->address); printf(" \n");
p=p->next;
}while(p!=NULL);
printf("==================================\n");
}
else
printf("通讯录为空,无法输出!\n");
}
//增加函数
struct address_list *insert(struct address_list *head)
{
struct address_list *p0,*p1,*p2;
char name[20];
p1=head;
printf("请输入增加的内容:\n");
printf("请输入姓名:");
gets(name);
if(strcmp(name,"0")==0)
{
printf("姓名不能为0,增加失败!\n");
return(head);
}
else
{
p0=(struct address_list *)malloc(LEN);
strcpy(p0->name,name);
printf("请输入职业:"); gets(p0->work);
printf("请输入手机:"); gets(p0->handset);
printf("请输入电子邮件:"); gets(p0->email);
printf("请输入通讯地址:"); gets(p0->address);
n=n+1;
if(head==NULL)
{
head=p0;
p0->next=NULL;
return head;
}
else
{
while(strcmp(p0->name,p1->name)>0&&(p1->next!=NULL))
{
p2=p1;
p1=p1->next;
}
if(strcmp(p0->name,p1->name)<0 || strcmp(p0->name,p1->name)==0)
{
if(head==p1)
{
head=p0;
}
else
{
p2->next=p0;
}
p0->next=p1;
}
else
{
p1->next=p0;
p0->next=NULL;
}
return head;
}
}
}
struct address_list* delete_txl(struct address_list *head)
{
struct address_list *p,*q;
char name[30];
if(head==NULL)
{
printf("通讯录为空,无法显示!\n");
return head;
}
p=head;
printf("请输入需要删除的人的姓名:");
gets(name);
if(strcmp(head->name,name)==0)
{
head=head->next;
free(p);
printf("删除操作成功!\n");
return head;
}
else
{
q=head,p=head->next;
while(p!=NULL)
{
if(strcmp(p->name,name)==0)
{
q->next=p->next;
free(p);
printf("删除操作成功!\n");
return head;
}
p=p->next;
q=q->next;
}
}
}
//显示函数
struct address_list *display(struct address_list *head)
{
struct address_list *p1,*p2;
char name[30];
int m;
if(head==NULL)
{
printf("通讯录为空,无法显示!\n");
return head;
}
p1=head;
m=0;
printf("请输入需要显示人的姓名:");
gets(name);
while(p1!=NULL)
{
while((strcmp(p1->name,name))!=0 && p1->next!=NULL)
{
p2=p1;
p1=p1->next;
}
if(strcmp(p1->name,name)==0)
{
m++;
printf("%s的通讯内容如下:\n",name);
printf("---姓名--------职业--------手机-------Email------通讯地址\n");
printf("==================================\n");
printf("== %s",p1->name);printf(" ");
printf("%s",p1->work);printf(" ");
printf("%s",p1->handset);printf(" ");
printf("%s",p1->email);printf(" ");
printf("%s",p1->address); printf(" \n");
printf("==================================\n");
}
p1=p1->next;
}
if(m==0)
{
printf("此人未在本通讯录中!\n");
}
return(head);
}
//排序函数
struct address_list *paixu(struct address_list *head)
{
struct address_list *p1,*p2;
int i,j;
struct address_list1
{
char name[30];
char work[30];
char handset[30];
char email[30];
char address[30];
};
struct address_list1 px[200];
struct address_list1 temp;
if(head==NULL)
{
printf("通讯录为空,无法排序!\n");
return(head);
}
p1=head;
for(i=0;i<n,p1!=NULL;i++)
{
strcpy(px[i].name,p1->name);
strcpy(px[i].work,p1->work);
strcpy(px[i].handset,p1->handset);
strcpy(px[i].email,p1->email);
strcpy(px[i].address,p1->address);
p2=p1;
p1=p1->next;
}
head=shifang(head);
for(j=0;j<n-1;j++)
{
for(i=j+1;i<n;i++)
{
if(strcmp(px[i].name,px[j].name)<0)
{
temp=px[i];
px[i]=px[j];
px[j]=temp;
}
}
}
p1=(struct address_list *)malloc(LEN);
p2=p1;
strcpy(p1->name,px[0].name);
strcpy(p1->work,px[0].work);
strcpy(p1->handset,px[0].handset);
strcpy(p1->email,px[0].email);
strcpy(p1->address,px[0].address);
head=p1;
for(i=1;i<n;i++)
{
p1=(struct address_list *)malloc(LEN);
strcpy(p1->name,px[i].name);
strcpy(p1->work,px[i].work);
strcpy(p1->handset,px[i].handset);
strcpy(p1->email,px[i].email);
strcpy(p1->address,px[i].address);
p2->next=p1;
p2=p1;
}
p2->next=NULL;
printf("按姓名排序后为:\n");
print(head);
return(head);
}
//姓名查找函数
struct address_list *search(struct address_list *head)
{
struct address_list *p1,*p2;
int m;
char name[30];
if(head==NULL)
{
printf("通讯录为空,无法分类查找!\n");
return(head);
}
p1=head;
printf("********************\n");
printf("** 请输入需要查找的姓名 **\n");
printf("********************\n");
m=0;
gets(name);
while(p1!=NULL)
{
while(strcmp(p1->name,name)!=0&&p1->next!=NULL)
{
p2=p1;
p1=p1->next;
}
if(strcmp(p1->name,name)==0)
{
m++;
printf("你查找的内容是:\n");
printf("+++++++++++++++++++++++++++++++++++\n");
printf("++ %s %s %s %s %s\n",p1->name,p1->work,p1->handset,p1->email,p1->address);
printf("+++++++++++++++++++++++++++++++++++\n");
}
p1=p1->next;
if(m==0)
{
printf("此人未在本通讯录中!\n");
}
break;
}
return(head);
}
//释放内存函数
struct address_list *shifang(struct address_list *head)
{
struct address_list *p1;
while(head!=NULL)
{
p1=head;
head=head->next;
free(p1);
}
return(head);
}
//文件写入函数
void save(struct address_list *head)
{
FILE *fp;
struct address_list *p1;
char tong[30];
if(head==NULL)
{
printf("通讯录为空,无法存储!\n");
return;
}
printf("请输入保存后的文件名:");
gets(tong);
fp=fopen("tong.txt","w");
if(fp==NULL)
{
printf("cannot open file\n");
return;
}
p1=head;
fprintf(fp,"姓名 职业 手机 Email 通讯地址\n");
for(;p1!=NULL;)
{
fprintf(fp,"%s %s %s %s %s\n",p1->name,p1->work,p1->handset,p1->email,p1->address);
p1=p1->next;
}
printf("保存完毕!\n");
fclose(fp);
}
这个是C语言通讯录的代码我想知道那个p2有什么作用。。创建函数那一块,总是把值赋给p2,,但是p2是怎么起作用的呢。