链表基础操作2

#include <iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
int readthedata(int a[] )
{
    FILE * r=fopen("1.txt","r");
    int j=0,k=0,temp,x,xp,counter=0;
    while(fscanf(r,"%d",&a[counter])!=EOF)
    {
         counter++;
    }
    for(j=0;j<counter;j++)
    {
        x=a[j];
        xp=j;
        for(k=j;k<counter;k++)
        {
            if(a[k]>x)
            {  x=a[k];
               xp = k ;
            }
        }
        temp = x;
        a[xp] = a[j];
        a[j] = temp ;
    }
    for(j=0;j<counter;j++) printf("%d",a[j]);
    //关闭文件
    fclose(r);
    return counter ;

}

struct node{
   int data;
   node* next ;
};

struct node* Create_link(int a[],int n)
{
    int i ;
    node *p,*pre,*head;  //我们一般说知道一个节点的位置，那么这个指针一定是指向这个节点的前一个节点，故pre超级重要
    head = new node;
    head->next = NULL;
    pre = head;
    for(i=0;i<n;i++)
    {
        p = new node;
        p->data = a[i];
        p->next =NULL;
        pre->next =p;
        pre=p;
    }
    printf("create successfully!\n");
    return head;
}
void findathing(int a,node *head)
{
    node *p ;
    int flag = 0;
    p = head->next ;
    while(p!=NULL)
    {
        if(p->data==a) flag = 1;
        p = p->next;
    }
    if(flag==1) printf("yep,we find it ");
    else printf("sorry,we can‘t find it");
}
void insertadata(node* head,int x)
{
    node *p ,*q ;
    q = new node ;
    q->data =x;
    q->next = NULL;
    p=head->next;
    while(p->next!=NULL) p=p->next;
    p->next = q;
    printf("insert successfully!\n");

}
void deleteadata(node* head ,int x)
{
    node *p ,*q;
    p=head->next;
    while(p!=NULL&&p->next->data!=x) p=p->next;
    if(p==NULL) printf("sorry,there is no such a data");
    if(p->next->data==x)
    {
        q=p->next;
        p->next=q->next;
        delete q;
        printf("delete successfully!\n");
    }
}
void printalink(node* head)
{
    node* p;
    p=head->next;
    while(p!=NULL)
    {
        printf("%d\n",p->data);
        p=p->next;
    }
    printf("printf successfully!\n");
}
int  calculatethedata(node *head)
{
    int counter=0;
    node *p ;
    p=head->next;
    while(p!=NULL)
    {
        p=p->next;
        counter++;
    }
    return counter ;
}
void reversethelink(node *head)
{
    node *p,*q ;
    p = head->next->next ;
    head->next->next = NULL;
    while(p)
    {
        q = p->next ;
        p->next = head->next ;
        head->next =p ;
        p=q;
    }
    printf("reverse successfullly");
}
int main()
{
    int a[100];
    node *head ;
    int n ,i;
    char ch ;

    printf("建立_C,插入_I,删除_D,显示_O,查找_F,反向_R,退出_E,统计长度_L\n");
    scanf("%c",&ch);
    while(ch!=‘E‘)
    {
    if(ch==‘C‘)
    {
        n = readthedata(a);
        head = Create_link(a,n);
    }
    if(ch==‘F‘)
    {
        printf("input the data you want to find");
        scanf("%d",&i);
        findathing(i,head);
    }
       if (ch==‘I‘)
    {
        printf("input the data you want to insert");
        scanf("%d",&i);
        insertadata(head,i);
    }
    if(ch==‘D‘)
    {
        printf("input the data you want to delete");
        scanf("%d",&i);
        deleteadata(head,i);
    }
    if(ch==‘O‘)
    {
        printalink(head);
    }
    if(ch==‘L‘)
    {
        printf("%d",calculatethedata(head));
    }
    if(ch==‘R‘)
    {
        reversethelink(head);
    }
    printf("建立_C,插入_I,删除_D,显示_O,查找_F,反向_R,退出_E,统计长度_L\n");
    scanf("%c",&ch);
    }


}