数结初学者的链栈，我实在找不出错在哪里，求大神帮忙

我想知道Creat函数里面到底发生什么了,为什么调试的结果这么乱,帮忙看看,谢谢啦
#include <stdio.h>                           
#include<malloc.h>                           
  typedef struct node
    {                        
       int data;                                 
       struct node *next;                        
    }Node,*Linkstack;                                                                       

  void Creat_Stack(Linkstack S)               
  {                                            
     int n,i;
     Node *p = S;                                   
     printf("please input the max n:\n");         
     scanf("%d\n",&n);
     for(i  =0;i < n;i++)                             
      {
        p->next = (Node*)malloc(sizeof(Node));        
        scanf("%d ",&p->data);                     
        p = p->next;
      }                                            
     p = NULL;
     p = S->next;
     while(p)
       {
          printf("%3d",p->data);
          p = p->next;
       }
  }                                             
                              
  void Push_Stack(Linkstack S,int e)            

  {                                            
     Node *p;
     p = (Node *)malloc(sizeof(Node));                                   
     p->data=e;                                   
     p->next=S->next;                             
     S->next=p;                                   
  }                                                                                         

  int  Pop_stack(Linkstack S,int *e)           
  {                                            
      Node *p;                                    
      if(S->next==NULL)
       {
          puts("It's a empty stack");
          return 0;
       }                 
     p=S->next;                                   
     *e=p->data;                                 
     S->next=p->next;                             
     free(p);                                    
     return 1;                                    
  }                                             
                                          
  int Pf(Linkstack S)                          
  {                                            
     Node *p;                                    
     p=S->next;                                 
     printf("\n");                              
     while(p!=NULL)                              
     {                                         
       printf("%d",p->data);
       p=p->next;                              
     }                                         
   }                                                                                          

  void main()                                 
  {                                            
     Linkstack N;                                
     int e,a;
     N = (Node *)malloc(sizeof(Node));
     N->next = NULL;
     Creat_Stack(N);
   /*  printf("please input what you want to push e:\n");
     scanf("%d\n",&e);                                                                       
     Push_Stack( N,e);                           
      printf("after pushing,the Linkstack is:\n");
    Pf(N);                                      
     Pop_stack( N, &a);                          
     printf("after poping,the Linkstack is:\n");
     Pf(N);   */                                   
     getch();
   }  
push 跟 pop两个函数我调试过,是对的