链表

#include "stdio.h"
#include "stdlib.h"
typedef struct number{
        long key;
        char name;
        int count;
        struct number *next;
}student;

struct number *add(long k,struct number *head){
        int flag=0;
        struct number *p=head;
        while(p!=NULL&&flag==0){
                if(p->key==k){
                        flag=1;
                }else p=p->next;
        }
        if(flag==1){
                p->count++;
        }else{
                p=head;
                head=(struct number *)malloc(sizeof(struct number));
                head->key=k;
                head->count=1;
                head->next=p;
        }
        return(head);
}
void list(struct number *head){
 struct number *p=head;
 while(p!=NULL){
        printf("%16ld %d\n",p->key,p->count);
        p=p->next;
        }
}
student *create(int n){
      student *s=(student *)malloc(sizeof(student));
      s->name='A';
      student *head=s;
      int i;
      for(i='B';i<'A'+n;i++){
        s=(s->next=(student *)malloc(sizeof(student)));
        s->name=i;
        s->next=NULL;
        }
      while(head){
        printf("%s\t",head->name);
        head++;
        }
}
student *reverse(student *head,student *pre){
        student *p=head->next;
        head->next=pre;
        if(p){
        reverse(p,head);
        }else{
        return head;
        }

}
main(){
 struct number *a=NULL;
 long k;int i=0;
 //printf("Input a number:");

//scanf("%ld\n",&k);

 //while(k>=0){

 //if(k<0) break;

 //a=add(k,a);

 //scanf("%ld\n",&k);

//}

 //list(a);

 student *head=create(6);
 reverse(head,NULL);
 return ;
}