【数据结构】宜宾大学-计院-实验五

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;

typedef int datatype;
//节点成员变量的建立
typedef struct QNode
{
	datatype data;
	struct QNode* Next;
}QNode, *QueuePtr;

//匿名结构体，成员变量为队列首尾指针
struct
{
	QueuePtr front = NULL;
	QueuePtr rear = NULL;
}Ptr;

//开辟一个新节点
QNode* BuyNode(datatype x)
{
	QNode* newnode = (QNode*)malloc(sizeof(QNode));
	if (newnode == NULL) return NULL;
	else
	{
		newnode->data = x;
		newnode->Next = NULL;
	}
	return newnode;
}

//初始化头节点
void InitHead(QueuePtr head)
{
	head = BuyNode(0);
	Ptr.front = head;
	Ptr.rear = head;
}

//销毁链式队列
void DestroyQueue(QueuePtr head)
{
	QueuePtr pcur = head;
	while (pcur)
	{
		QueuePtr next = pcur->Next;
		free(pcur);
		pcur = next;
	}
}

//队列插入元素的实现（即入队列）
void push(datatype x)
{
	QueuePtr node = BuyNode(x);
	Ptr.rear->Next = node;
	Ptr.rear = node;
}

//队列元素的删除（即头删）
void pop()
{
	QueuePtr del = Ptr.front->Next;
	if (del == NULL)
	return;
	else
	{
		QueuePtr next = del->Next;
		Ptr.front->Next = next;

		free(del);
		del = NULL;
	}
}

//判空
bool EmptyQueue()
{
	if (Ptr.front->Next == NULL)
		return true;
	else
		return false;
}

//获取队列首元素（即出队列）
datatype GetHead()
{
	if (Ptr.front->Next == NULL)
	return 0;
	else
	return Ptr.front->Next->data;
}

//队列当前元素个数
int SizeQueue()
{
	int count = 0;
	QueuePtr pcur = Ptr.front->Next;
	while (pcur)
	{
		count++;
		QueuePtr next = pcur->Next;
		pcur = pcur->Next;
	}
	return count;
}

int main()
{
	QueuePtr head = NULL;
	InitHead(head);
	push(1);
	push(2);
	push(3);
	push(4);
	push(5);
	push(6);
	push(7);
	push(8);

	cout << "队列中当前元素的个数：" << SizeQueue() << endl << endl;
	cout << "依次输出队列中所有元素：" << endl;
	while (!EmptyQueue())
	{
		cout << GetHead() << " ";
		pop();
	}
	cout << endl << endl;
	cout << "销毁队列：" << endl;
	DestroyQueue(head);
	cout << "销毁队列后队列中的元素个数：" << SizeQueue();
	return 0;
}