随机点名系统源程序ok

#include

#include

#include

#define SIZE 4

struct student

{char num[20];

char name[20];

int time;

}std[SIZE];

void save()

{int i;

FILE *fp;

if((fp=fopen("myfile.dat","rb+"))==NULL)

{printf("文件打开失败\n");

exit(0);}

for(i=0;i

if(fwrite(&std[i],sizeof(struct student),1,fp)!=1)

/*将内存中的数据输出到磁盘文件中*/

printf("文件保存失败\n");

}

void main()

{

int j,i;

char c;

FILE *fp;

/*if((fp=fopen("myfile.dat","wb+"))==NULL)

{

printf("文件打开失败\n");

exit(0);

}

for(i=0;i

scanf("%s %s %d",std[i].name,std[i].num,&std[i].time);

for(i=0;i

fwrite(&std[i],sizeof(struct student),1,fp);

fclose(fp);*///第一次运行写入名字

if((fp=fopen("myfile.dat","ab+"))==NULL)

{

printf("文件打开失败\n");

exit(0);

}

for(i=0;i

fread(&std[i],sizeof(struct student),1,fp);

/*将fp所指向的文件中的数据存储到数组std中*/

printf("*************欢迎使用上课随机点名程序**************\n");

printf("*************输入a：显示所有同学名情况*************\n"); printf("*************输入d: 开始点名**********************\n"); printf("*************输入s：保存点名**********************\n"); printf("*************输入b: 点名次数归零******************\n"); printf("*************输入q: 退出**************************\n"); printf("***************************************************\n"); while(1)

{

c=getchar();

switch(c)

{

case 'a':for(i=0;i

printf("\t\t%s\t\t%s\t\t被点名%d次\n",std[i].num,std[i].name,std[i].time); break;

case 's': save();

printf("****文件保存成功！退出请输入q****\n");

break;

case 'b': for(i=0;i

std[i].time=0;

printf("点名次数归%d\n",std[i].time);break;

case 'q': exit(0);

case 'd':

loop:j=rand()/1000; /*调用rand的函数进行点名*/

if(j==0)

{

std[0].time++;

printf("\t\t%s\t\t%s\n",std[j].num,std[j].name);

}

else if(j==1)

{

std[1].time++;

printf("\t\t%s\t\t%s\n",std[j].num,std[j].name);

}

else if(j==2)

{

std[2].time++;

printf("\t\t%s\t\t%s\n",std[j].num,std[j].name);

}

else if(j==3)

{

std[3].time++;

printf("\t\t%s\t\t%s\n",std[j].num,std[j].name);

}

else goto loop;

break;}

}

fclose(fp); }

运行结果：