queue.c

自己做的常用库和实现的数据结构。public domain.

/* Demo of simplest queue data structure.
 *
 * Written by Cyril Hu ([e-mail]), public domain.
 */
#include<my.h>
#define MAX 10
typedef struct q_node {
	int data;
	struct q_node *next;
} Q_NODE, *q_node_ptr;
typedef struct queue {
	q_node_ptr front;
	q_node_ptr rear;
} QUEUE;

void init_queue(QUEUE *p)
{
	p->front = p->rear = (q_node_ptr)mem('m', sizeof(Q_NODE));
	p->front->next = NULL;
}

void en_queue(QUEUE *p, const q_node_ptr q)
{
	q_node_ptr t = (q_node_ptr)mem('m', sizeof(Q_NODE));
	t->data = q->data;
	t->next = NULL;
	p->rear->next = t;
	p->rear = t;
}

int queue_empty(QUEUE *p)
{
	return p->front != p->rear ? 0 : 1;
}
void de_queue(QUEUE *p, q_node_ptr q)
{
	q_node_ptr t;
	if(! queue_empty(p)) {
		if( (t = p->front->next) == p->rear)
			p->rear = p->front;
		p->front->next = t->next;
		q->data = t->data;
		free(t);
	}
}
void destroy_queue(QUEUE *p)
{
	while( p->front != NULL) {
		p->rear = p->front->next;
		free(p->front);
		p->front = p->rear;
	}
}

int main()
{
	int i;
	QUEUE a, *p = &a;
	Q_NODE b[MAX], c[MAX];
	init_queue(p);
	for(i=0; i<MAX; i++) {
		b[i].data = i;
		en_queue(p, &b[i]);
	}
	for(i=0; i<MAX; i++) {
		de_queue(p, &c[i]);
		printf("%d ", c[i].data);
	}
	destroy_queue(p);
	return 0;
}