queue.cpp

来自「掌握循环队列的基本操作及在顺序存储结构上的实现。数据结构」· C++ 代码 · 共 133 行

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include "Queue.h"

void QueueInitial(LinkQueue pQ)
{
	QueueNode *p;
	Apply(p);
	if (NULL==p)
	{
		printf("内存分配失败!");
		exit(1);
	}
	pQ->front=p;
	pQ->rear=pQ->front;
    pQ->front->next=NULL;
}

int IsEmpty(LinkQueue pQ)
{
	return pQ->front==pQ->rear;
}

void EnQueue(LinkQueue pQ,ElemType e)
{
	QueueNode *p;
	Apply(p);
	if (NULL==p)
	{
		printf("内存分配失败!");
		exit(1);
	}
	p->data=e;
	p->next=NULL;
	pQ->rear->next=p;
	pQ->rear=p;
}

ElemType DeQueue(LinkQueue pQ)
{
	QueueNode *first;
	ElemType temp;
	if (IsEmpty(pQ))
	{
		printf("空队!\n");
        exit(1);  
	}
	first=pQ->front->next;
	temp=first->data;
	pQ->front->next=first->next;
	if (first->next==NULL)
	{
		pQ->rear=pQ->front;
	}
	free(first);
	return temp;
}

ElemType GetFront(LinkQueue pQ)
{
	QueueNode *first;
	if (IsEmpty(pQ))
	{
		printf("空队!");
		exit(1);
	}
	first=pQ->front->next;
	return first->data;
}

void display(LinkQueue pQ)
{
	QueueNode *first;
	if (IsEmpty(pQ))
	{
		printf("空队!");
	}
	while (!IsEmpty(pQ))
	{
		printf("%-5c",GetFront(pQ));
		first=pQ->front->next;
		pQ->front->next=first->next;
		if (first->next==NULL)
		{
		    pQ->rear=pQ->front;
		}
	}
	putchar('\n');
}

void MakeEmpty(LinkQueue pQ)
{
	QueueNode *p,*q;
	p=pQ->front->next;
	while (p!=NULL)
	{
		q=p;
		p=p->next;
		free(q);
	}
	pQ->front->next=NULL;
	pQ->rear=pQ->front;
}

void Destroy(LinkQueue pQ)
{
	QueueNode *p,*q;
	p=pQ->front;
	if (p!=NULL)
	{
		q=p;
		p=p->next;
		free(q);
	}
	pQ->front=pQ->rear=NULL;
}

void Union(LinkQueue pQ1,LinkQueue pQ2)//将队列pQ2所指的队列中的元素加到pQ1所指的队列的队尾
{
	QueueNode *first;
	while (!IsEmpty(pQ2))
	{
		EnQueue(pQ1,GetFront(pQ2));
	    first=pQ2->front->next;
		pQ2->front->next=first->next;
		if (first->next==NULL)
		{
		    pQ2->rear=pQ2->front;
		}
	}
}