queue

// ConsoleApplication8.cpp: определяет точку входа для консольного приложения.
//


#include "stdafx.h"
#include "iostream"
#include "string"
#include "sstream"
#include "Windows.h"
#include "iomanip"

template <typename T>
class queue
{
    struct Node
    {
        T value;
        size_t priority;
        Node *next, *prev;
    };
    Node *head, *tail;
public:
    queue()
    {
        head = tail = nullptr;
    }
    queue(const queue& q)
    {
        Node* helpPtr(q.tail);
        while (helpPtr) {
            push(helpPtr->value, helpPtr->priority);
            helpPtr = helpPtr->prev;
        }
    }
    ~queue()
    {
        Node* helpPtr(head);
        while (helpPtr) {
            Node* buf(helpPtr);
            delete helpPtr; helpPtr = buf;
        }
    }
    void push(T val, size_t prt)
    {
        Node* newNode(new Node);
        newNode->value = val;
        newNode->priority = prt;
        if (head) {
            Node* helpPtr(head);
            while (helpPtr && helpPtr->priority < prt)
                helpPtr = helpPtr->next;
            if (!helpPtr) {
                newNode->next = nullptr;
                tail->next = newNode;
                newNode->prev = tail;
                tail = newNode;
                return;
            }
            if (helpPtr == head) {
                newNode->prev = nullptr;
                head->prev = newNode;
                newNode->next = head;
                head = newNode;
                return;
            }
            newNode->prev = helpPtr->prev;
            newNode->next = helpPtr->next;
            helpPtr->prev->next = newNode;
            helpPtr->prev = newNode;
            newNode->next = helpPtr;
        }
        else {
            newNode->prev = newNode->next = nullptr;
            head = tail = newNode;
        }
    }
    T pop()
    {
        T val(tail->value);
        delete tail;
        return val;
    }
    void print()
    {
        Node* helpPtr(head);
        std::cout << "{ ";
        while (helpPtr) {
            std::cout << helpPtr->value << " ";
            helpPtr = helpPtr->next;
        }
        std::cout << "}" << std::endl;
    }
    void print()
    const {
        Node* helpPtr(head);
        std::cout << "{ ";
        while (helpPtr) {
            std::cout << helpPtr->value << " ";
            helpPtr = helpPtr->next;
        }
        std::cout << "}" << std::endl;
    }
    void clear()
    {
        Node* helpPtr(head);
        while (helpPtr) {
            Node* buf(helpPtr->next);
            delete helpPtr; helpPtr = buf;
        }
        head = tail = nullptr;
    }
    queue& operator= (const queue& q)
    {
        clear();
        Node* helpPtr(q.tail);
        while (helpPtr) {
            push(helpPtr->value, helpPtr->priority);
            helpPtr = helpPtr->prev;
        }
        return *this;
    }
    friend const queue  operator + (const queue& q1, const queue& q2){
        queue newQ(q1);
        Node* helpPtr(q2.tail);
        while (helpPtr) {
            newQ.push(helpPtr->value, helpPtr->priority);
            helpPtr = helpPtr->prev;
        }
        return queue(newQ);
    }
};
/*template <typename T>
class printer
{
    queue<T> userName, text;
    size_t count;
public:
    printer() { count = 0; }
    void send(std::string u, std::string s, size_t p)
    {
        userName.push(u, p);
        text.push(s, p);
        count++;
    }
    void print()
    {
        std::cout << "Printing:" << std::endl;
        for (size_t i = 0; i < count; i++) {
            std::cout << "Username: " << userName.pop() << std::endl;
            std::cout << "Text: " << text.pop() << std::endl;
        }
        count = 0;
    }
};*/
int main()
{
    system("color F0");
    queue<int> a, b, d, z;
    a.push(2, 0);
    a.push(4, 3);
    a.push(1, 0);
    a.push(3, 2);
    std::cout << "a: "; a.print();
    b.push(1, 4);
    const queue< int> c(a);
    c.print();
    d = a;
    std::cout << "b: "; b.print();
    z = a + b;
    std::cout << "c = "; c.print();
    std::cout << "a: "; a.print();
    std::cout << "b: "; b.print();
    std::cout << "d: "; d.print();
    /*c = a * b;
    std::cout << "a * b = "; c.print();
    printer<std::string> q;
    q.send("User 3", "You", 1);
    q.send("User 1", "Are", 2);
    q.send("User 2", "How", 3);
    q.send("User 3", "?", 1);
    q.print();*/
    system("pause");
}