【数据结构】-初阶-队列

queue.h

#include 
#include 
#include 


typedef int QDatatype;

typedef struct QueueNode
{
	QDatatype data;
	struct QueueNode * next;
}QueueNode;

typedef struct Queue
{
	QueueNode* head;
	QueueNode* tail;
}Queue;

void QueueInit(Queue * pq);

void QueueDestory(Queue* pq);

void QueuePush(Queue* pq, QDatatype x);

void QueuePop(Queue* pq);

QDatatype QueueFront(Queue* pq);
QDatatype QueueBack(Queue* pq);

int QueueEmpty(Queue* pq);
int QueueSize(Queue* pq); 

queue.c

#include "queue.h"

void QueueInit(Queue * pq)
{
	assert(pq);
	pq->head = pq->tail = NULL;
}

void QueueDestory(Queue* pq)
{
	assert(pq);
	QueueNode* cur = pq->head;
	while (cur)
	{
		QueueNode* next = cur->next;
		free(cur);
		cur = next;
	}
	pq->head = pq->tail = NULL;
}

void QueuePush(Queue* pq, QDatatype x)
{
	assert(pq);
	QueueNode* newnode = (QueueNode*)malloc(sizeof(QueueNode));
	if (newnode == NULL)
	{
		printf("内存不足\n");
		exit(-1);
	}
	newnode->data = x;
	newnode->next = NULL;
	if (pq->head == NULL)
	{
		pq->head = pq->tail = newnode;
	}
	else
	{
		pq->tail->next = newnode;
		pq->tail = newnode;
	}


}

void QueuePop(Queue* pq)
{
	assert(pq);
	assert(pq->head);
	QueueNode* next = pq->head->next;
	free(pq->head);
	pq->head = next;
	if (pq->head == NULL)
	{
		pq->tail = NULL;
	}
}

QDatatype QueueFront(Queue* pq)
{
	assert(pq);
	assert(pq->head);
	return pq->head->data;
}
QDatatype QueueBack(Queue* pq)
{
	assert(pq);
	assert(pq->head);
	return pq->tail->data;
}

int QueueEmpty(Queue* pq)
{
	assert(pq);
	return pq->head == NULL ? 1 : 0;
}
int QueueSize(Queue* pq)
{
	assert(pq);
	QueueNode* cur = pq->head;
	int size = 0;
	while (cur)
	{
		size++;
		cur = cur->next;
	}
	return size;
}```