#include <stdio.h>
#include <malloc.h>
struct students * create(int n);//链表的建立
void print(struct students *head);//链表的输出
struct students * del(struct students *head,int num);
struct students
{
    char name[20];
    int number;
    int sco;
    struct students *next;
};
int main()
{
    struct students *head;int n,num;
    printf("请输入学生人数:");scanf("%d",&n);
    head=create(n);
    printf("请输入要删除的编号：");scanf("%d",&num);
    head=del(head,num);
    printf("\n删除后：\n\n");
    print(head);
    return 0;
}
struct students * del(struct students *head,int num)
{
    struct students *p1,*p2;
    if(head==NULL)
    {
        printf("原表为空！\n");
        return (NULL);
    }
    else
    {
    p1=head;
    while(p1->number!=num&&p1->next!=NULL)
    {
        p2=p1;
        p1=p1->next;
    }
    if(p1->number==num)
    {
        if(p1==head)
        head=p1->next;
        else
        p2->next=p1->next;
        printf("\n学号为%d的学生已经删除\n",num);

    }
    else
    printf("学号为%d的学生不存在\n",num);
    return (head);
    }
}
struct students * create(int n)
{
    struct students *head=NULL,*p1,*p2;
    int i;
    for(i=1;i<=n;i++)
    {
        p1=(struct students *)malloc(sizeof(struct students));
        printf("请输入第%d个学生的姓名，学号，成绩\n",i);
        scanf("%s%d%d",p1->name,&p1->number,&p1->sco);
        p1->next=NULL;
        if(i==1) head=p1;
        else p2->next=p1;
        p2=p1;

    }

    return head;
}
void print(struct students *head)
{
    struct students *p=head;
    printf("姓名      学号      成绩\n");
    while(p!=NULL)
    {
        printf("%4s     %4d     %4d\n",p->name,p->number,p->sco);
        p=p->next;

    }
}