Cyclic linked lists-C_ data structure

#define NULL ((void *) 0) #define MALLOC (DataType, N) MALLOC (sizeof (dataType) *n) #define SCANF (PVal, Val) SCANF ( "%d", &val) #define FREE (point) #define EXIT (Val) exit (val) typedef struct node{int da
	Ta 
struct Node *pnext;

}node_t, *pnode_t;
pnode_t create_loop_list (void);
void Traverse_loop_list (pnode_t phead);
BOOL Insert_loop_list (pnode_t phead, int pos, int val);
BOOL Delete_loop_list (pnode_t phead, int pos, int *val);
void Sort_loop_list (pnode_t phead, int length);


int Loop_list_length (pnode_t phead);
	int main (void) {int val;
	pnode_t Phead;
	
  Phead = Create_loop_list ();
	Insert_loop_list (Phead, 1, 22);
	Insert_loop_list (Phead, 1, 44);
	Insert_loop_list (Phead, 1, 55);
	Insert_loop_list (Phead, 1, 66);
	Insert_loop_list (Phead, 1, 33);
	Insert_loop_list (Phead, 1, 77);
	Insert_loop_list (Phead, 1, 88);

  Insert_loop_list (Phead, 1, 99);
	Traverse_loop_list (Phead);
	
	Sort_loop_list (Phead, Loop_list_length (Phead)); Traverse_loop_liSt (Phead);
	if (Delete_loop_list (Phead, 1, &val)) {printf ("Delete Success, val =%d\n", Val);
	}else{printf ("Delete fail!\n");
	} if (Delete_loop_list (Phead, 6, &val)) {printf ("Delete Success, val =%d\n", Val);
	}else{printf ("Delete fail!\n");
	} if (Delete_loop_list (Phead, 2, &val)) {printf ("Delete Success, val =%d\n", Val);
	}else{printf ("Delete fail!\n");
	
	} traverse_loop_list (Phead);
return 0;
	
	} pnode_t create_loop_list (void) {pnode_t phead = (pnode_t) MALLOC (node_t, 1);
		if (NULL = = Phead) {printf ("Allocation fail!\n");
	EXIT (-1);
		}else{pnode_t ptail = (pnode_t) MALLOC (node_t, 1);
			if (NULL = = Phead) {printf ("Allocation fail!\n");
		EXIT (-1);
			}else{ptail->data = 0;
			Ptail->pnext = Phead;
		Phead->pnext = Ptail;
	return phead;
	} void Traverse_loop_list (pnode_t phead) {pnode_t p = phead->pnext;
	printf ("Traverse result:\n");
		while (P!= phead) {printf ("%xh:%d\n", p,p->data);
	p = p->pnext;
	}Return
	int Loop_list_length (pnode_t phead) {int cnt = 0;
	
	pnode_t p = phead->pnext;
		while (P!= phead) {p = p->pnext;
	cnt++;

} return CNT;
	Insert a new node in front of the node in the//pos position, POS greater than 0 bool Insert_loop_list (pnode_t phead, int pos, int val) {int i = 0;

	pnode_t p = phead;
		while ((P->pnext!= phead) && (i < pos-1)) {p = p->pnext;
	i++;
	}//printf ("-Insert_loop_list-%xh, i:%d, pos:%d\n", P,i,pos); if ((P->pnext = = Phead) | | (i > Pos-1))
	
	return false;
	pnode_t pnew = (pnode_t) MALLOC (node_t, 1);
	Pnew->data = val;

	Pnew->pnext = p->pnext;

	P->pnext = pnew;
return true;
	//delete the node at POS position in the cyclic list, assign the data field value of the node to (*val) bool Delete_loop_list (pnode_t phead, int pos, int *val) {int i = 0;

	pnode_t p = phead;
		while ((P->pnext!= phead) && (i < pos-1)) {p = p->pnext;
	i++; } if ((P->pnext = = Phead) | | (i > Pos-1))

	return false;
	
	pnode_t Pbuff = p->pnext;
	(*val) = p->pnext->data; P->pnext = P-&GT;PNEXT-&GT;pnext;

	Free (pbuff);
return true;
	BOOL Is_empty (pnode_t phead) {if (NULL = = Phead->pnext) return true;
else return false;
	} void Sort_loop_list (pnode_t phead, int length) {if (Is_empty (Phead)) {printf ("List is empty!\n");
		}else{int I, J, T;
		pnode_t p, q; For (i=0,p=phead->pnext; i<length-1; I++,p=p->pnext) {for (j=i+1,q=p->pnext; j<length; j++,q=q->pNe
					XT) {if (P->data > Q->data) {t = p->data;
					P->data = q->data;
				Q->data = t;
}}} return;
 }