/* Demo of loop queue, using dynamic array. * * Written by Cyril Hu (cyrilhu@gmail.com), public domain. */#include "my.h"#define QUEUE_INIT_SIZE 10#define QUEUE_INCREMENT 20#define MAX 40typedef int ElemType;typedef size_t OrderTag;typedef struct {	ElemType e;	OrderTag tag;} QNode, *QNodePtr;typedef struct {	QNodePtr head;	size_t queuesize;} Queue, *QueuePtr;void InitQueue(QueuePtr p){ 	QNodePtr q, t;	p->head = (QNodePtr)mem('m', (p->queuesize = QUEUE_INIT_SIZE) * sizeof(QNode));	printf("%p\n", p->head);	q = p->head, t = p->head + p->queuesize - 1;	for(; q <= t; q->tag = 0, q++);}void EnQueue(QueuePtr p, ElemType data){	static size_t cnt = 0;	QNodePtr q = p->head, t = p->head + p->queuesize - 1;	for(; q <= t; q++)		if(q->tag == 0) {			q->e = data;			q->tag = ++cnt;			return;		}	p->head = (QNodePtr)mem('r', p->head, (p->queuesize + QUEUE_INCREMENT) * sizeof(QNode));	printf("%p\n", p->head);	q = p->head + p->queuesize;	p->queuesize += QUEUE_INCREMENT;	t = p->head + p->queuesize - 1;	q->e = data;	q->tag = ++cnt;	for(q++; q <= t; q->tag = 0, q++);}void DeQueue(QueuePtr p, ElemType *data){	QNodePtr q = p->head, t = p->head + p->queuesize - 1, r = q;	static bool queueemptyflag = false;	if(queueemptyflag)		return;	for(queueemptyflag = true; q < t; q++)		if(q->tag != 0 && r->tag > (q+1)->tag) {			r = q+1;			queueemptyflag = false;		}	if(queueemptyflag && q->tag == 0)		queueemptyflag = true;	if(! queueemptyflag) {		*data = r->e;		r->tag = 0;	}}void DestroyQueue(QueuePtr p){	free(p->head);}int main(void){	Queue b, *p = &b;	int i,a[MAX];	InitQueue(p);	for(i=0; i<MAX; i++)		EnQueue(p, i);	for(i=0; i<MAX*2; i++)		DeQueue(p, &a[i]);	for(i=0; i<MAX; i++)		printf("%d ", a[i]);	DestroyQueue(p);	return 0;}