linkqueue

#ifndef __LINKQUEUE_H__
#define __LINKQUEUE_H__

#include <stdio.h>
#include <stdlib.h>

typedef struct linklist {
	int data;
	struct linklist *next;
}linklist_t;

typedef struct linkqueue {
	linklist_t *front, *rear;
}linkqueue_t;

linkqueue_t *create_linkqueue(void);
int 	is_empty_linkqueue(linkqueue_t *q);
int 	in_linkqueue(linkqueue_t *q, int x);
int 	out_linkqueue(linkqueue_t *q);
void 	show_linkqueue(linkqueue_t *q);

#endif


#include "linkqueue.h"

linkqueue_t *create_linkqueue(void)
{
	linkqueue_t *q = (linkqueue_t *)malloc(sizeof(linkqueue_t));
	q->front = q->rear = (linklist_t *)malloc(sizeof(linklist_t *));
	q->front->next = NULL;

	return q;
}

int is_empty_linkqueue(linkqueue_t *q)
{
	return q->front == q->rear;
}

int in_linkqueue(linkqueue_t *q, int x)
{
	int ret = (q != NULL);

	if (ret)
	{
		linklist_t *node = (linklist_t *)malloc(sizeof(linklist_t));
		node->data = x;
		node->next = NULL;

		q->rear->next = node; // 指向
		q->rear = node; // 移动
	}

	return ret;
}

int out_linkqueue(linkqueue_t *q)
{
	if (is_empty_linkqueue(q))
	{
		puts("q is empty \n");
		return -1;
	}

	int ret = (q != NULL);
	if (ret)
	{
		linklist_t *del = q->front->next;
		ret = del->data;

		q->front = q->front->next;

		free(del);
		del = NULL;
	}

	return ret;
}

void show_linkqueue(linkqueue_t *q)
{
	if (is_empty_linkqueue(q))
	{
		puts("q is empty \n");
		return;
	}

	linklist_t *p = q->front;
	while(p->next)
	{
		printf("%d \n", p->next->data);
		p = p->next;
	}

	putchar(10);
}


int main(int argc, const char *argv[])
{
	int i = 0;
	linkqueue_t *q = create_linkqueue();
	
	for (i = 0; i < 10 ; i++)
		in_linkqueue(q, i);

	show_linkqueue(q);

	for (i = 0; i < 14; i++)
		out_linkqueue(q);

	show_linkqueue(q);

	return 0;
}