#include <stdlib.h>
#include <stdio.h>
typedef struct singlylooplist_s{
	int id;
	struct singlylooplist_s* next;
	void* contentaddress;
}singlylooplist;

singlylooplist* initlooplist(int id,void* contentaddress){
	singlylooplist* cursor=(singlylooplist*)malloc(sizeof(singlylooplist));
	cursor->next=cursor;
	cursor->id=id;
	cursor->contentaddress=contentaddress;
	return cursor;
}
singlylooplist* addlistnode(singlylooplist* cursor,int id,void* contentaddress){
	if(cursor==NULL)
		return NULL;
	singlylooplist* previousnode = cursor;
	singlylooplist* latternode=cursor->next;
	cursor=(singlylooplist*)malloc(sizeof(singlylooplist));
	cursor->id=id;
	cursor->contentaddress=contentaddress;
	cursor->next=latternode;
	previousnode->next=cursor;
	return cursor;
}
singlylooplist* searchlistnode(singlylooplist* cursor,int id){
	if(cursor==NULL)
		return NULL;
	if(cursor->id==id)
		return cursor;
	singlylooplist* originnode=cursor;
	while(cursor->next!=originnode)
		if(cursor->next->id==id)
			return cursor->next;
		else
			cursor=cursor->next;
	return NULL;
}
void deletelistnode(singlylooplist** cursor,int id){
	singlylooplist* deletenode=searchlistnode(*cursor,id);	
	singlylooplist *latternode,*previousnode;
	if(deletenode==NULL)
		return;
	previousnode=deletenode;
	latternode=deletenode->next;
	while(previousnode->next!=deletenode)
		previousnode=previousnode->next;
	if(deletenode->contentaddress!=NULL)
		free(deletenode->contentaddress);
	deletenode->contentaddress=NULL;
	previousnode->next=latternode;
	//printf("delete node id = %d !\n",deletenode->id);
	if(deletenode->next==deletenode)
		*cursor=NULL;
	else
		*cursor=previousnode;
	free(deletenode);
}
void deleteallnode(singlylooplist** cursor){
	if(*cursor==NULL)
		return;
	singlylooplist* originnode=*cursor;
	singlylooplist* deletenode=(*cursor)->next;
	while(deletenode!=originnode){
		*cursor=deletenode->next;
		if(deletenode->contentaddress!=NULL)
			free(deletenode->contentaddress);
		deletenode->contentaddress=NULL;
		free(deletenode);
		deletenode=*cursor;
	}
	if(originnode->contentaddress!=NULL)
		free(originnode->contentaddress);
	originnode->contentaddress=NULL;
	free(originnode);
	*cursor=NULL;
}
int countlooplist(singlylooplist* cursor){
	int count=0;
	if(cursor==NULL)
		return count;
	count=1;
	singlylooplist *originnode=cursor;
	for(cursor=cursor->next;originnode!=cursor;count++)
		cursor=cursor->next;
	return count;
}

/*
typedef struct people_s{
	char name[33];
	int age;
}people;
#include <string.h>
main(){
	people* p1 = malloc(sizeof(people));
	strcpy(((people *)p1)->name,"peng si ming");
	((people *)p1)->age = 27;
	printf("people name = %s and age = %d\n",((people *)p1)->name,((people *)p1)->age);
	printf("size of people=%d\n",sizeof(people));
	singlylooplist* head=initlooplist(3,NULL);
	addlistnode(head,1,p1);
	addlistnode(head,2,NULL);
	printf("node count = %d\n",countlooplist(head));
	searchlistnode(head,2);
	searchlistnode(head,0);
	searchlistnode(head,3);
	p1=(people*)(searchlistnode(head,1)->contentaddress);
	printf("search ok\n");
	deletelistnode(&head,2);
	deletelistnode(&head,3);
	printf("people name = %s and age = %d\n",p1->name,p1->age);
	//deleteallnode(&head);
	deletelistnode(&head,1);
	printf("list address = %d people name = %s and age = %d\n",searchlistnode(head,1),p1->name,p1->age);
	deletelistnode(&head,1);
	deletelistnode(&head,12);
	printf("delete node ok...........\n");
	printf("delete all node after = %d\n",countlooplist(head));
}
*/