【数据结构】队列的出队和入队操作

队列的操作规则是先进先出，要注意一下，

1.队列为空

2.队列只有一个元素，即头尾指针都指向空

3.初始化队列时，分配空间后不要忘记将头为指针置空

// 13_4.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <string.h>
#include <conio.h>
#include <stdio.h>
#include <iostream>
using namespace std;

typedef struct student
{
	int data;
	struct student *next;
}node;

typedef struct linkqueue
{
	node *first,*rear;
}queue;

queue *insert(queue *HQ,int x)
{
	node *p = (node *)malloc(sizeof(node));
	p->data = x;
	p->next = NULL;
	if (NULL == HQ->rear)
	{
		HQ->first = p;
		HQ->rear = p;
	}
	else
	{
		HQ->rear->next = p;
		HQ->rear = p;
	}
	cout << HQ->rear->data << endl;
	return HQ;
}

queue *del(queue *HQ)
{
	node *p;
	int x;
	if (NULL == HQ)
	{
		cout << "Queue is null!" << endl;
	}
	else
	{
		p = HQ->first;
		x = HQ->first->data;
		if (HQ->first == HQ->rear)
		{
			HQ->rear = NULL;
			HQ->rear = NULL;
			free(p);
		}
		else
		{
			HQ->first = HQ->first->next;
			free(p);
		}
		cout << x << endl;
	}
	return HQ;
}

int _tmain(int argc,_TCHAR* argv[])
{
	linkqueue *seq = (linkqueue *)malloc(sizeof(linkqueue));
	seq->rear = NULL;
	seq->first = NULL;
	cout << "The inserted seq is: n" << endl;
	for (int i = 0; i < 10; i++)
	{
		seq = insert(seq,i);
	}

	cout << "The deleted seq is: n" << endl;
	for (int i = 0; i < 10; i++)
	{
		seq = del(seq);
	}
	return 0;
}

输出：

The inserted seq is:


0
1
2
3
4
5
6
7
8
9
The deleted seq is:


0
1
2
3
4
5
6
7
8
9
请按任意键继续. . .

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!