这里的使用结构嵌套应该怎样用啊？我这是错的
#include <stdio.h>

int main()
{
struct mark{
float class1;
float class2;
float class3;
};
struct student
{
char name[20];
int id;
struct mark;
};
struct student stu[5];
int i;
float ave,total=0;
printf("please input:\n");
for(i=0;i<5;i++){
printf("Name:");
scanf("%s",&stu[i].name);
printf("ID:");
scanf("%d",&stu[i].id);
printf("Class1:");
scanf("%f",&stu[i].mark.class1);
printf("Class2:");
scanf("%f",&stu[i].mark.class2);
printf("Class3:");
scanf("%f",&stu[i].mark.class3);
total+=stu[i].mark;
}
ave=total/5.0;
for(i=0;i<5;i++){
printf("%s %d %-10.2f",stu[i].name,stu[i].id,stu[i].mark);
printf("\n");
}
printf("\n%g\n",ave);
return 0;
}

#include <stdio.h>

int main()
{
struct mark{
float class1;
float class2;
float class3;
};
struct student
{
char name[20];
int id;
struct mark Mark;
};
struct student stu[5];
int i;
float ave,total=0;
printf("please input:\n");
for(i=0;i<5;i++){
printf("Name:");
scanf("%s",&stu[i].name);
printf("ID:");
scanf("%d",&stu[i].id);
printf("Class1:");
scanf("%f",&stu[i].Mark.class1);
printf("Class2:");
scanf("%f",&stu[i].Mark.class2);
printf("Class3:");
scanf("%f",&stu[i].Mark.class3);
total+=stu[i].mark;
}
ave=total/5.0;
for(i=0;i<5;i++){
printf("%s %d ",stu[i].name,stu[i].id);
printf("%10.2f %10.2f %10.2f",stu[i].Mark.class1,stu [i].Mark.class2,stu[i].Mark.class3);
printf("\n");
}
printf("\n%g\n",ave);
return 0;
}

哦，懂了！谢谢啊！