c链表的一些问题

dong50252409 · 发表于 2011-8-10 00:59:51

马上注册，结交更多好友，享用更多功能^_^

您需要登录才可以下载或查看，没有账号？立即注册

x

本帖最后由 dong50252409 于 2011-8-10 12:10 编辑

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#define LEN sizeof(struct student)
struct student
{
char num[6], name[20], sex[3];//定义学号、姓名、性别
float math, english, politics, chinese, sum;//定义数学、英语、**、语文、总分
struct student *next;
};
int n;//全局变量，用于记录每个班级学生人数
void menu()
{
system("cls");//清屏
printf("-------------------------------------------------------------------------------");
printf("\n 学生数据管理系统\n");
printf("\n [0]退出\n");
printf("\n [1]创建学生数据\n");
printf("\n [2]添加学生数据\n");
printf("\n [3]删除学生数据\n");
printf("\n [4]查询\n");
printf("-------------------------------------------------------------------------------");
}
// 等待用户按回车后回到主菜单
void to_menu()
{
char c1, c2;
printf("\n\n\n按回车键返回主菜单...");
scanf("%c%c",&c1,&c2);//第一个字符吸收上次的确认回车键
menu();
}
//打印
void list(struct student *head, char c_name[20])
{
struct student *p;
p = head;
system("cls");
printf("\n---------------------------[%s]学生成绩表----------------------------\n",c_name);
printf("\n\t学号\t姓名\t性别\t数学\t英语\t**\t语文\t总分\n");
while(p != NULL)
{
printf("\n\t%s\t%s\t%s\t%.1f\t%.1f\t%.1f\t%.1f\t%.1f\n",p->num,p->name,p->sex,p->math,p->english,p->politics,p->chinese,p->sum);
p = p->next;
}
printf("\n班级共%d名学生!",n);
}
//保存
void save_data(struct student *head, char c_name[20])
{
FILE *fp;
struct student *p;
p = head;
if((fp = fopen(c_name,"wb")) == NULL)
{
printf("\n不能保存指定文件!");
exit(0);
}
while(p->next != NULL)//当next等于NULL时表明已经是最后一块数据，退出
{
fwrite(p, sizeof(struct student), 1, fp);
p = p->next;
}
fclose(fp);
list(head, c_name);
}
//载入
void load_data(char c_name[20])
{
FILE *fp;
struct student *p, *last, *head;//p工作指针、last最后一项指针、head头指针
head = NULL;
head = (struct student *)malloc(LEN);
last = head;
if((fp = fopen(c_name,"rb")) == NULL)
{
printf("\n不能打开指定文件!");
exit(0);
}
while(!feof(fp))
{
p = (struct student *)malloc(LEN);
if((fread(p, sizeof(struct student), 1, fp)) == 1)
{
last->next = p;
last = p;
}
}
fclose(fp);
last->next = NULL;//表示文件结束
/*return head = head->next;*///临时
}
void add_data()
{
FILE *fp;
struct student *p1,*p2,*head;
char c_name[20];//存放班级名
char ch1, ch2;//判定是否继续输入学生信息
n = 0;
printf("\n请输入班级名:");
scanf("%s",c_name);
fp = fopen(c_name,"wb");//创建班级数据文件
//head = NULL;
while(ch2 != '0')
{
n++;
if(n == 1)
{
p1 = (struct student *)malloc(LEN);
printf("\n学号:");
scanf("%s",p1->num);
printf("\n姓名:");
scanf("%s",p1->name);
printf("\n性别:");
scanf("%s",p1->sex);
printf("\n数学成绩:");
scanf("%f",&p1->math);
printf("\n英语成绩:");
scanf("%f",&p1->english);
printf("\n**:");
scanf("%f",&p1->politics);
printf("\n语文成绩:");
scanf("%f",&p1->chinese);
p1->sum = p1->math + p1->english + p1->politics + p1->chinese;
printf("\n学号\t姓名\t性别\t数学\t英语\t**\t语文\t总分\n");
printf("------------------------------------------------------------\n");
printf("%s\t%s\t%s\t%.1f\t%.1f\t%.1f\t%.1f\t%.1f\n",p1->num, p1->name, p1->sex, p1->math, p1->english, p1->politics, p1->chinese, p1->sum);
head = p1;
p1->next = NULL;
LOOP1: printf("\n按0结束,回车继续输入!\n");
printf("\n请输入:");
scanf("%c%c",&ch1,&ch2);
if( ch2 != '0' && ch2 != '\n')//判断如果输入的字符不为0或回车，报错并从新输入
{
printf("\n输入错误!请从新输入!");
goto LOOP1;
}
}
else
{
p2 = p1;
p1 = (struct student *)malloc(LEN);
printf("\n学号:");
scanf("%s",p1->num);
printf("\n姓名:");
scanf("%s",p1->name);
printf("\n性别:");
scanf("%s",p1->sex);
printf("\n数学成绩:");
scanf("%f",&p1->math);
printf("\n英语成绩:");
scanf("%f",&p1->english);
printf("\n**:");
scanf("%f",&p1->politics);
printf("\n语文成绩:");
scanf("%f",&p1->chinese);
p1->sum = p1->math + p1->english + p1->politics + p1->chinese;
printf("\n学号\t姓名\t性别\t数学\t英语\t**\t语文\t总分\n");
printf("------------------------------------------------------------\n");
printf("%s\t%s\t%s\t%.1f\t%.1f\t%.1f\t%.1f\t%.1f\n",p1->num, p1->name, p1->sex, p1->math, p1->english, p1->politics, p1->chinese, p1->sum);
p2->next = p1;
LOOP2: printf("\n按0结束,回车继续输入!\n");
printf("\n请输入:");
scanf("%c%c",&ch1,&ch2);
if( ch2 != '0' && ch2 != '\n')//判断如果输入的字符不为0或回车，报错并从新输入
{
printf("\n输入错误!请从新输入!");
goto LOOP2;
}
}
}
p1->next= NULL;
fclose(fp);
save_data(head,c_name);
return head;
}
void main()
{
struct student *p;
char fun;
menu();
while(1)
{
printf("请输入功能号[0-4]:");
scanf("%c",&fun);
switch(fun)
{
case '0': break;
case '1':
{
p = add_data();
to_menu();
}
}
if(fun == '0')
{
break;
}
}
}

复制代码

184行为什么不能返回return的值呢？

rainymay · 发表于 2011-8-10 08:45:50

void add_data()
怎么能返回呢

dong50252409 · 发表于 2011-8-10 09:53:37

那怎样才能返回呢

zfzhuman123 · 发表于 2011-8-10 10:07:35

既然你返回的是一个指向结构的指针，那就struct student *add_data();

dong50252409 · 发表于 2011-8-10 10:17:50

谢谢呵呵呵

账号		自动登录	找回密码
密码			立即注册