#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
struct node
{ int data;
 struct node *next;
};

node *creat()
{  node *head,*p,*q;
   int x,cycle=1;
   head=(node*)malloc(sizeof(node));
   head->next=NULL;
   p=head;
   while(cycle)
   {
       printf("\n请输入一个数:");
       scanf("%d",&x);
       if(x!=0)
       {  
           q=(node*)malloc(sizeof(node));
           q->data=x;
           q->next=p->next;
           p->next=q;
           p=q;
       }
       else
           cycle=0;
   }
   return head;
}
void export(node *head)
{      node *p;
      for(p=head->next;p;p=p->next)
          printf("%5d",p->data);
          printf("\n");
}

node *search(node *head,int i)
{    node *p;
   int j=0;
   p=head;
 
   while(j<i&&p->next)
   { p=p->next;
    j++;
   }
   if(j==i)
      return p;
   else
       return NULL;
}
node *search1(node*head,int x)
{ node *p;
  p=head;
  while(p->next&&p->next->data!=x)
      p=p->next;
      if(p->next)
          return p->next;
          else
          return NULL;
}
void insert(node *head,int x)
{ node *p,*q;
  int i,j=0;
  printf("请输入插入的位置i:");
 scanf("%d",&i);
  p=head;
 while(j<i-1&&p->next)
 { p=p->next;
  j++;
 }
 if(j==i-1)
 {
     q=(node*)malloc(sizeof(node));
     q->data=x;
     q->next=p->next;
     p->next=q;
 }
 else
     printf("\n插入失败");
 export(head);
}
void Delete(node *head,int i)
{ node *p,*q;
  int j=0;
  p=head;
  while(p->next&&j<i-1)
  {  p=p->next;
    j++;
  }
  if(j==i-1)
  {
      q=p->next;
      p->next=q->next;
      free(q);
  }
  else
      printf("\n无法删除");
export(head);
}
void Delete1(node *head,int x)
{
    node *p,*q;
    p=head;
    while(p->next&&p->next->data!=x)
        p=p->next;
    if(p->next->data==x)
    {
        q=p->next;
        p->next=q->next;
        free(q);
    }
    else
        printf("\n无法删除");
    export(head);
}
void main()
{   
    node *head;
    creat();
    int i,x,chioce,chioce1,n,b,a,c;
    printf("请选择:1->查找;2->插入;3->删除\n");
    scanf("%d",&chioce);
    if(chioce==1)
    {
        printf("请选择1,按位置;2,按值;\n");
         scanf("%d",&chioce1);
         if(chioce1==1)
         {
             printf("请输入查找的位置i:");
            scanf("%d",&i);
           search(head,i);
         }
   
         else
         {
           printf("请输入查找的值x:");
           scanf("%d",&x);
           search1(head,x);
         }
    }
   else if(chioce==2)
   {   
       printf("请输入插入的数为c:");
       scanf("%d",&c);
        
            insert(head,c);
   }
   else
   {   printf("请选择:1->按位置;2->按值\n");
       scanf("%d",&n);
       if(n==1)
       {
           printf("请输入查找的位置b:\n");
           scanf("%d",&b);
           Delete(head,b);
       }
       else
       {
           printf("请输入查找的值a:\n");
           scanf("%d",&a);
           Delete1(head,a);
       }
   }
}