Lab5_1

#include <iostream>

using namespace std;

struct node {
    node* next;
    int info;
};

void push(node*& Begin, node*& End) {
    node* el = new node;
    cout << "Значение: ";
    cin >> el->info;
    el->next = NULL;
    if (End == nullptr) {
        Begin = End = el;
    }
    else {
        End = el;
    }
}


bool isEmpty(node* Begin) {
    if (Begin == nullptr)
        cout << "Очередь пуста\n";
    return Begin == nullptr;
}

void queueList(node* Begin) {
    if (isEmpty(Begin))
        return;
    node* temp = Begin;
    while (temp != nullptr) {
        cout << temp->info << " ";
        temp = temp->next;
    }
}

void pop(node*& Begin) {
    if (isEmpty(Begin))
        return;
    node* temp = Begin;
    temp = Begin;
    Begin = Begin->next;
    delete temp;
}

int peek(node* Begin) {
    if (isEmpty(Begin))
        return -1;
    return Begin->info;
}


int main() {
    setlocale(LC_ALL, "Rus");
    node* Begin = nullptr, * End = nullptr;
    push(Begin, End);
    push(Begin, End);
    push(Begin, End);
    queueList(Begin);
    pop(Begin);
    cout << endl;
    queueList(Begin);
    cout << endl;
    int num = peek(Begin);
    cout << num;
}