链表之有头链表

//有头链表
#include <stdio.h>
#include <string.h>
#include <malloc.h>
#define N   sizeof(struct student)
 struct student
{ char name[20];
  int num;
  int score;
 
  struct student * next;
 
};
struct student * creat_list(int n);
void print_list(struct student* head);
void add_list(struct student* head);
void delete_list(struct student* head);
void sort_list(struct student* head);
 
 
int main (void)
{ struct student * Head;
  int n;
  scanf("%d",&n);    //输入你需要创建链表的长度
  Head=creat_list(n);//返回头结点的地址 创建链表
  print_list(Head);  //发送头节点的地址   输出链表
  add_list(Head);   //发送头节点的地址   插入
  delete_list(Head); //发送头节点的地址 删除
  sort_list(Head);  //发送头节点的地址  链表排序（这里是升序）
  print_list(Head);  //发送头节点的地址 再次输出
 
  return 0;
}
struct student * creat_list(int n)
{ int i=1;
  struct student *head,*p0,*p1;
  head=p0=(struct student* )malloc(N);//动态创建一块内存记为头结点
  p1=(struct student* )malloc(N);//动态创建一块内存记为首结点；
  scanf("%d %s %d",&p1->num,p1->name,&p1->score);
  while(i<n)
  { p0->next=NULL;
    p1->next=p0->next;
    p0->next=p1;
    p0=p1;
    p1=(struct student * )malloc(N);
    scanf("%d %s %d",&p1->num,p1->name,&p1->score);
    i++;
  }
  p0->next=p1;
  p1->next=NULL;
  return head;
 
}
void print_list(struct student* head)
{
  struct student *p0;
  p0=head->next;
  while(p0!=NULL)
  { printf("%s %d %d\n",p0->name,p0->num,p0->score);
    p0=p0->next;
  }
}
void add_list(struct student* head)
{
  struct student*p0,*p1=head;
  p0=(struct student* )malloc(N);
  scanf("%d %s %d",&p0->num,p0->name,&p0->score);
  head=head->next;
  while(head!=NULL)
  {
    if(head->num>p0->num)//插在链表的头结点后边或中间
    {   p0->next=p1->next;
        p1->next=p0;
        break;
    }
    p1=head;
    head=head->next;
  }
  if(head==NULL)//插在链表的最后
  { head->next=p0;
    p0->next=NULL;
  }
 
}
void delete_list(struct student* head)
{ struct student *p1=head;
  int num;
  scanf("%d",&num);
  head=head->next;
  while(head!=NULL)
  {
    if(head->num==num)
    {
      p1->next=head->next;
      free(head);
      break;
    }
 
    p1=head;
    head=head->next;
  }
  if(head==NULL)
  {
    p1->next=NULL;
    free(head);
  }
  
}
void sort_list(struct student* head)
{
  struct student *p0,*p1,*p2;
  char a[10];
  int m,n;
  for(p0=head->next;p0!=NULL;p0=p0->next)
  { p2=p0;
    for(p1=p0->next;p1!=NULL;p1=p1->next)
    {
      if(p2->num>p1->num)//升序排序
      {
        p2=p1;      
      }
    }
    if(p2!=p0)
    { m=p0->num;
      p0->num=p2->num;
      p2->num=m;
      strcpy(a,p0->name);
      strcpy(p0->name,p2->name);
      strcpy(p2->name,a);
      n=p0->score;
      p0->score=p2->score;
      p2->score=n;
    }
  }
  
}