#include<stdio.h>
# define maxsize 50
 struct sqlist
 {
     int sqlist[maxsize];
    int size;
         
 };

 setnull(struct sqlist *p)  /*装入表*/
 {
     p->size=0;
 }
 
 int length(struct sqlist *p)  /*表长度*/
 {
      return(p->size);
 }
 
 get(struct sqlist *p,int i)  /*读取元素*/
 {
        if (i<1 && i>p->size)
            printf("错误");
          else
              printf("该序号对应的元素为：%d",p->sqlist[i-1]);
 }
 
 locate(struct sqlist *p,int x)  /*查找元素*/
 {  
     int i=1;
        while (i<=p->size && p->sqlist[i-1]!=x)
            i++;
            
          if (i==p->size+1 )
              printf("错误");
    else printf("该元素第一次出现的位置：%d",i);
 }
 
 insert(struct sqlist *p,int i,int x)
 {
     int j;
         if (i<1 && i>p->size+1)
        printf("位置不正确不能行插入\n");
     else
      {
        
        for (j=p->size-1;j>=i;j--)
            p->sqlist[j]=p->sqlist[j-1];
        p->sqlist[j-1]=x;
        p->size++;
      }
     for(j=1;j<=p->size;j++)
         printf("%d ",p->sqlist[j-1]);
 }
 
 void delete(struct sqlist *p,int i)
 {
     int j;
     if (i<1 || i>p->size)
        printf("错误");
     else
    {
         for (j=i;j<p->size;j++)
            p->sqlist[j-1]=p->sqlist[j];
        p->size--;
     }
     printf("此线性表为：\n");
       for (i=1;i<=p->size;i++)
        printf("%d ",p->sqlist[i-1]);
 }

 

display(struct sqlist *p)
{
    int j;
    if (p->size==0)
        printf("此表为空无法显示！");
    else
        printf("the list");
    if (p->size==1)
        printf("%d",p->sqlist[p->size-1]);
     else
     {
         for(j=1;j<=p->size;j++)
             printf("%d ",p->sqlist[j-1]);
        
     }
}

main()
{
    int i,select,a,j;int w;
    struct sqlist *p;
    struct sqlist l;
    setnull(&l);
    printf("请输入数据：\n");
     p=&l ;
      p->size=0;
      for (i=1;i<5; i++)
         {
             scanf("%d",&l.sqlist[i-1]);
             p->size++;
         }
    printf("\n");
    printf("1:置空表！ \n");
      printf("2:求长度！ \n");
      printf("3:读取元素！ \n");
      printf("4:定位查找！ \n");
      printf("5:插入！ \n");
      printf("6:删除！ \n");
      printf("7:显示！ \n");

      printf("请选择（1----8） \n");
      scanf("%d",&select);
      switch(select)
    {
        case 1:
            setnull(&l);break;
        case 2:
            printf("chang du %d",length(&l));
            break;
        case 3:
            printf("输入序号:");
            scanf("%d",&i);
            get(&l,i);
            break;
        case 4:
            printf("输入元素:");
            scanf("%d",&i);
            locate (&l,i);
            break;
        case 5:
            printf("输入插入的元素及位置：");
            scanf("%d,%d",&i,&j);
                 insert(&l,i,j);
                 break;
        case 6:
            printf("输入所要删除数据的位置:");
                   scanf("%d",&w);
                   delete(&l,w);   
                   break;
        
        case 7:
            display(&l);  
            break;
      }
}