数据结构_链队列

//LinkQueue.h
#ifndef LinkQueue_H
#define LinkQueue_H
#define NULL 0
struct Node{
int data;
Node* next;
};

class LinkQueue{
public:
LinkQueue();  //构造
~LinkQueue();  //析构
void Enqueue(int x);// 插入
int DeQueue();  // 删除队首
int GetQueue();  //取队首元素
int Empty();  //判空操作
private:
Node* front;  //队首指针
Node* rear;  //队尾指针
};

#endif;

//LinkQueue.cpp
#include "LinkQueue.h"

LinkQueue::LinkQueue(){
Node* s = NULL;
s = new Node;
s->next = NULL;
front = rear = s;
}

LinkQueue::~LinkQueue(){
Node* p = NULL;
while(front!=NULL)
{
p = front->next;
delete front;
front = p;
}
}

void LinkQueue::Enqueue(int x){
Node* s = NULL;
s = new Node;
s->data = x;
s->next = NULL;
rear->next = s; rear = s;
}

int LinkQueue::DeQueue(){
Node* p = NULL;
int x;
if(rear == front) throw "下溢";
p = front->next;
x = p->data;
front->next = p->next;
if(p->next == NULL) rear = front;
delete p;
return x; 
}

int LinkQueue::GetQueue(){
if(front!=rear) return front->next->data;
else return -(1<<30);  //错误标记
}

int LinkQueue::Empty(){
if(front == rear) return 1;
return 0;
}

//LinkQueue_main.cpp
#include<iostream>
using namespace std;
#include "LinkQueue.h"

int main(){
LinkQueue Q;
if(Q.Empty()) cout << "队列为空" << endl;
else cout << "队列非空" << endl;
cout << "元素10和15执行入队操作：" << endl;
try{
Q.Enqueue(10);
Q.Enqueue(15);
}
catch(char* wrong){
cout << wrong << endl;
}
cout << "查看队首元素" << endl;
cout << Q.GetQueue() << endl;
cout << "执行出队操作" << endl;
try{
Q.DeQueue();
}
catch(char* wrong) {
cout << wrong << endl;
}
cout << "查看队首元素" << endl;
cout << Q.GetQueue() << endl;
return 0;
}