싱글 체인 시계 (표 두 결점)

#include 
#include 

#define OK              0
#define ERROR          -1
#define MALLOC_ERROR   -2

typedef int ElementType;       //c     ElementType      ，      ，             
typedef struct node
{
	ElementType data;          //     
	struct node *next;         //    
}Node;
typedef Node *PNode;           //         

//       
int Create_List_Head(PNode h, ElementType data)
{
	if (h == NULL)
	{
		return ERROR;
	}
	
	PNode node =  (PNode)malloc(sizeof(Node)/sizeof(char));
	if (node == NULL)
	{
		return MALLOC_ERROR;
	}
	node->data = data;
	node->next = h->next;
	h->next = node;
	
	return OK;
}

//       
int Create_List_Tail(PNode h, ElementType data)
{
	if (h == NULL)
	{
		return ERROR;
	}
	
	PNode node = (PNode)malloc(sizeof(Node)/sizeof(char));
	if (node == NULL)
	{
		return MALLOC_ERROR;
	}
	node->data = data;
	node->next = NULL;
	
	//       
	PNode temp = h;
	while (temp->next)
	{
		temp = temp->next;
	}
	temp->next = node;
	
	return OK;
}

//  pos          
int Insert_Node(PNode h, int pos, ElementType data)
{
	PNode temp = h;
	int k = 0;
	
	// pos-1   
	while (temp && k < pos-1)
	{
		temp = temp->next;
		k++;
	}
	
	if (temp == NULL)        //  
	{
		printf ("      
");
		return ERROR;
	}
	
	PNode node = (PNode)malloc(sizeof(Node)/sizeof(char));
	if (node == NULL)
	{
		return MALLOC_ERROR;
	}
	node->data = data;
	node->next = temp->next;
	temp->next = node;
	
	return OK;
}

//       pos   
int Delete_Node(PNode h, int pos)
{
	PNode temp = h;
	int k = 0;
	
	//            ，  temp
	while (temp && k < pos-1)
	{
		temp = temp->next;
		k++;
	}
	
	if (temp == NULL || temp->next == NULL)        //  
	{
		printf ("      
");
		return ERROR;
	}
	
	PNode p = temp->next;
	temp->next = p->next;
	free(p);
	p = NULL;
	
	return OK;
}

//    
int Inverse_List(PNode h)
{
	//h == NULL           ，  
	//h->next == NULL        
	//h->next->next == NULL          
	if (h->next == NULL || h->next->next == NULL)
	{
		return OK;
	}
	
	
	PNode pre = h->next;
	PNode cur = pre->next;
	PNode next = NULL;
	
	while(cur)
	{
		next = cur->next;
		cur->next = pre;
		pre = cur;
		cur = next;
	}
	
	/* h->next->next == NULL;      //     ！！！，                 
	h->next = pre;              //              ，      next
	
	return OK; */
	
	h->next->next = NULL;
	h->next = pre;              //              ，      next
	
	return OK;
}	
	
//        ，           
PNode Search(PNode h, ElementType data)
{
	if (h == NULL)
	{
		return NULL;
	}
	
	PNode temp = h->next;
	while(temp)
	{
		if (temp->data == data)
		{
			return temp;
		}
		temp = temp->next;
	}
	
	return NULL;
}	

//       
int ListLen(PNode h)
{
	int len = 0;
	PNode temp = h->next;
	while(temp)
	{
		temp = temp->next;
		len++;
	}
	
	return len;
}	

//  
void Display(PNode h)
{
	if (h == NULL)
	{
		return;
	}
	PNode temp = h->next;       //         
	while (temp)
	{
		printf ("%4d",temp->data);
		temp = temp->next;
	}
	
	printf ("
");
}

int main()
{
	PNode head_node = (PNode)malloc(sizeof(Node)/sizeof(char));
	if (head_node == NULL)
	{
		return MALLOC_ERROR;
	}
	head_node->next = NULL;      //   
	
	int i = 0;
	for (i = 0; i < 10; i++)
	{
		/* //       
		  if (Create_List_Head(head_node,i) != OK)
		  {
			  return ERROR;
		  } */
		
		//       
		if (Create_List_Tail(head_node,i) != OK)
		{
			return ERROR;
		}
		
	}
	
	/* //  pos          
	if (Insert_Node(head_node, 6, 7) != OK)
	{
		return ERROR;
	}
	
	//       pos   
	if (Delete_Node(head_node,4) != OK)
	{
		return ERROR;
	} */
	
	//     
	if (Inverse_List(head_node) != OK)
	{
		return ERROR;
	}
	
	Display(head_node);
	
	//    
	PNode p = Search(head_node, 5);
	if(p == NULL)
	{
		printf("    
");
	}
	else
	{
		printf("%d
",p->data);
	}
	
	//    
	int len = ListLen(head_node);
	printf("%d
",len);
	
	return 0;
}