//初始化
QueueType QueueInit(Queue* pq);
//进队
void QueuePush(Queue* pq, int x);
//出队
void QueuePop(QNodepq);
//返回队头
QueueType QueueFront(Queue* pq);
//返回队尾
QueueType QueueBack(Queue* pq);
//返回对列的长度
int QueueSize(Queue* pq);
//判断队列是否为空
bool QueueEmpty(Queue* pq);
//队列的销毁
void QueueDsetory(Queue* pq);

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<assert.h>
#include<stdbool.h>
typedef int QueueType;
typedef struct QueueNode
{
  struct QueueNode* next;
  QueueType data;
}QNode;
typedef struct Queue
{
  QNode* head;
  QNode* tail;
}Queue;

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

void QueuePush(Queue* pq, int x)
{
  assert(pq);
  QNode* newnode = (QNode*)malloc(sizeof(QNode));
  if (newnode == NULL)
  {
    printf("内存开辟失败\n");
    exit(-1);
  }
  newnode->data = x;
  newnode->next = NULL;
  if (pq->tail == NULL)
  {
    pq->head = pq->tail = newnode;
  }
  else
  {
    pq->tail->next = newnode;
    pq->tail = newnode;
  }
}

void QueuePop(Queue*pq)
{
  assert(pq);
  assert(pq->head);
  if (pq->head->next == NULL)
  {
    free(pq->head);
    pq->head = pq->tail = NULL;
  }
  else//防止出现野指针
  {
    QNode* next = pq->head->next;
    free(pq->head);
    pq->head = next;
  }
}

QueueType QueueFront(Queue* pq)
{
  assert(pq);
  assert(pq->head);
  return pq->head->data;
}

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

int QueueSize(Queue* pq)
{
  assert(pq);
  int size = 0;
  QNode* cur = pq->head;
  while (cur)
  {
    ++size;
    cur = cur->next;
  }
  return size;
}

bool QueueEmpty(Queue* pq)
{
  assert(pq);
  return pq->head == NULL;
}

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