#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();
}
//排序
void *sort(struct student *head)
{
struct student *first, *tail, *p_min, *min, *p;//分别是排列后的有序链的表头指针、排列后的有序链的表尾指针、保留键值更小的前驱借点的指针、存储最小节点、当前比较的节点
first = NULL;
while(head != NULL) //在链表中找键值最小的节点
{
for(p = head, min = head;p->next != NULL;p = p = p->next)//遍历链表中的节点，找出此时最小的节点
{
if((strcmp(p->next->num, min->num)) < 0)//找到一个比当前min小的节点
{
p_min = p;//保存找到节点的前驱节点：显然p->next的前驱节点是p。
min = p->next;//保存键值更小的节点。
}
}
if(first == NULL)/*如果有序链表目前还是一个空链表*/
{
first = min;/*第一次找到键值最小的节点。*/
tail = min;/*注意：尾指针让它指向最后的一个节点。*/
}
else /*有序链表中已经有节点*/
{
tail->next = min;/*把刚找到的最小节点放到最后，即让尾指针的next指向它。*/
tail = min;/*尾指针也要指向它。*/
}
if(min == head) /*如果找到的最小节点就是第一个节点*/
{
head = head->next; /*显然让head指向原head->next,即第二个节点，就OK*/
}
else /*如果不是第一个节点*/
{
p_min->next = min->next; /*前次最小节点的next指向当前min的next,这样就让min离开了原链表。*/
}
}
if(first != NULL) /*循环结束得到有序链表first*/
{
tail->next = NULL;/*单向链表的最后一个节点的next应该指向NULL*/
}
head = first;
return head;
}
//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
if((fp = fopen(c_name,"rb")) == NULL)
{
printf("\n不能打开指定文件!");
return NULL;//如果文件不存在或无法打开返回空地址
}
head = (struct student *)malloc(LEN);
last = head;
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;
}
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);
}
//添加数据
void insert()
{
char c_name[20];
struct student *fun;//用于判断要打开的文件是否存在
struct student *p, *head;
LOOP3 : printf("\n请输入要插入数据的班级名:");
scanf("%s",c_name);
fun = load_data(c_name);
if(fun == NULL)
{
printf("\n请从新输入!");
goto LOOP3;
}
head = fun;//把头指针赋给head
p = (struct student *)malloc(LEN);//开辟存储单元
printf("\n学号:");
scanf("%s",&p->num);
printf("\n姓名:");
scanf("%s",&p->name);
printf("\n性别:");
scanf("%s",&p->sex);
printf("\n数学成绩:");
scanf("%f",&p->math);
printf("\n英语成绩:");
scanf("%f",&p->english);
printf("\n**:");
scanf("%f",&p->politics);
printf("\n语文成绩:");
scanf("%f",&p->chinese);
p->sum = p->math + p->english + p->politics + p->chinese;
p->next = head;
head = p;
head = sort(head);
n++;
save_data(head, c_name);
}
void main()
{
char fun;
menu();
while(1)
{
printf("请输入功能号[0-4]:");
scanf("%c",&fun);
switch(fun)
{
case '0': break;
case '1':
{
add_data();
to_menu();
}
case '2':
{
insert();
}
}
if(fun == '0')
{
break;
}
}
}
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狗仔卡
发表于 2011-8-10 16:28:24
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