데이터 구조...

#include
#include

struct student {
int id;
float grade;
};
typedef struct student;

struct NODE {
student data;
NODE* next;
};

struct List{
NODE* head;
NODE* tail;
};

void FirstLast(List& rlist)
{
NODE* p = new NODE;
p->next=NULL;
rlist.head=p;
rlist.tail=p;
};
void Adddata(List& rlist,student data)
{
NODE* p= new NODE;
p->data = data;
p->next = NULL;
rlist.tail -> next = p;
rlist.tail =p;
}

int main(void)
{
int num,i;
student stu;
List list;
FirstLast(list);

for(i=0;i<10;++i)
{ printf("Enter your id, grade.\n");
 stu.id=(int*)malloc(sizeof(int));
stu.grade=(float*)malloc(sizeof(float*));
scanf("%d %s",&stu.id,&stu.grade);
Adddata(list,stu);
 }
int rank=0;
student tmp;
 //성적 순서
 for(i=0;i<10;++i)
{ tmp=list.head;
 if(tmp.grade=='A')
printf("%d,%s",tmp.id,tmp.grade);
 list.head->next;
}
for(i=0;i<10;++i)
{ tmp=list.head;
 if(tmp.grade=='B')
 printf("%d,%s",tmp.id,tmp.grade);
 list.head->next;
}
for(i=0;i<10;++i)
 { tmp=list.head;
 if(tmp.grade=='C')
printf("%d,%s",tmp.id,tmp.grade);
 list.head->next;
}
for(i=0;i<10;++i)
{ tmp=list.head;
if(tmp.grade=='D')
printf("%d,%s",tmp.id,tmp.grade);
 list.head->next;
}
for(i=0;i<10;++i) {
tmp=list.head;
 if(tmp.grade=='F')
 printf("%d,%s",tmp.id,tmp.grade);
 list.head->next;
}

int ttk=0;

//학번순서

for(ttk=0;ttk<10;ttk++) { for(i=0;i<10;++i) { tmp=list.head; if(rank>tmp.id)
continue
else if(rank=tmp.id)
continue
else if(rank<next;
}
printf("%d,%s",tmp.id,tmp.grade);
}
return 0;
}



어디를 고쳐야 되는지 설명 해주실분...
내가 쓴거지만 뭔소린지 모르겟음..