c++课设

#include <stdio.h>
#include <time.h>
#include <math.h>
#define C 60000;
struct Student
{
char name[20];
int num;
char banji[10];
int time;
int feiyong;
};
void menu()
{
printf("\t\t\t*******************\n");
printf("\t\t\t\t1、输入 ******** \n");
printf("\t\t\t\t2、查询 *********\n ");
printf("\t\t\t\t3、使用显示****** \n");
printf("\t\t\t\t4、退出 *********** \n ");
printf("\t\t\t*******************\n");
}
int main()
{
clock_t start,finish; double TheTimes;
struct Student stu[30] ; int i,j,d,e,f;char na[20];
printf("\t\t\t\t***** 欢迎进入机房收费管理系统 ****\n ") ;
while(1)
{
menu();
printf("\t请输入你的选择：");
scanf("%d",&i) ;
switch(i)
{
case 1: for(int i=0;i<30;i++)
{
printf("请输入学号：");
scanf("%d",&stu[i].num);
printf("\n 请输入班级：");
scanf("%s",stu[i].banji);
printf("\n请输入姓名：");
scanf("%s",stu[i].name);
printf("\n请输入上机时间：");
scanf("%d",&stu[i].time);
stu[i].feiyong=0;
}
start=clock()
;break;
case 2:

printf(" 1、按学号查询：");
printf("\n2、按姓名查询：\n");
scanf("%d",&e);
if(e==1)
{
printf(" 请输入要查询的学号：");
scanf("%d",&d);
for(j=0;j<30;j++)
{
if( stu[j].num==d)
{
finish=clock();
TheTimes=(double)(finish-start)/C;
printf("你上来%f分钟\n",TheTimes);
}
}
}
else if(e==2)
{
printf(" 请输入要查询的姓名：");
scanf("%s",na);
for(j=0;j<30;j++)
{
if( stu[j].name==na)
{
finish=clock();
TheTimes=(double)(finish-start)/C;
printf("你上来%f分钟\n",TheTimes);
}
}
}
; break;

case 3: for(j=0;j<30;j++)
{
finish=clock();
TheTimes=(double)(finish-start)/C;
stu[j].feiyong=(TheTimes/60)*1;

}
for(j=0;j<30;j++)
{
printf("学号：%d",&stu[j].num);
printf("\n 班级：%s",stu[j].banji);
printf("\n姓名：%s",stu[j].name);
printf("\n上机时间：%d",&stu[j].time);
printf("\n费用：%d",&stu[j].feiyong);
printf("\n请输入上机时间：%d",&stu[j].time);
printf("\n");

}

;break;
case 4:return 0;break;
}
}

return 0;
}