数据结构自己实现——Linklist

//单???链???表???
#include <iostream>
using namespace std;

typedef char datatype;
typedef struct node{
                datatype data;
                 struct node* next;
}listnode;
typedef listnode* linklist;
listnode *p;

//建??立???链???表???
linklist createlist()
{
                linklist head = (listnode*)malloc( sizeof(listnode));
                listnode *p,*r;
                r = head;
                 char ch;
                 while((ch=getchar())!='\n' )
                {
                                p = (listnode*)malloc( sizeof(listnode));
                                 if(p==NULL)
                                                 return NULL;
                                p->data = ch;
                                r->next = p;
                                r = p;
                }
                r->next = NULL;
                 return(head);
}

//查??找??单???链???表???
linklist getnode(linklist head , int i)
{
                 int j;
                listnode* p;
                p = head;
                j = 0;
                 while(p->next && j<i)
                {
                                p = p->next;
                                j++;
                }
                 if(i==j)
                                 return p;
                 else
                                 return NULL;
}

//打???印??输??出?链???表???内??容?Y
void printlist(linklist head)
{
                listnode* p = head;
                 while(p->next)
                {
                                cout<<p->next->data<<endl;
                                p = p->next;
                }
}
//插?入??
void insertlist(linklist head,datatype m,int i)
{
                listnode* p = getnode(head,i);
                listnode* s = (listnode*)malloc( sizeof(listnode));
                s->data = m;
                 if(p!=NULL)
                {
                                s->next = p->next;
                                p->next = s;
                }
}
//删??除y一??个?结??点??,删??除y第???i个?后??面?的??那?个?
void deletelistnode(linklist head,int i)
{
                 int j = 0;
                listnode *p,*r;
                p = head;
                 while(p&&j<i)
                {
                                p = p->next;
                                j++;
                }
                 if(p==NULL)
                                exit(1);
                
                r = p->next;
                p->next = r->next;
                free(r);
                
}
int main()
{
                linklist mylist = createlist();
 //   listnode * tmp = getnode(mylist,3);
                 //cout<<tmp->data<<endl;
                 //printlist(mylist);
                 //insertlist(mylist,'a',2);
                 //printlist(mylist);
                deletelistnode(mylist,2);
                printlist(mylist);
                 return 0;
}