#include<iostream>
#include<stack>
#include<exception>
std::ostream &operator<<(std::ostream &tok,std::stack<int> s)
{
    while(!s.empty())
    {
        tok<<s.top()<<" ";
        s.pop();
    }
    return tok;
}
std::stack<int> operator-(std::stack<int> s1, std::stack<int> s2)
{
    if(s1.size()!=s2.size()) throw std::logic_error("NeS MOC");
    std::stack<int>s3;
    int razlika;
    while(!s1.empty())
    {
        razlika=s1.top()-s2.top();
        s3.push(razlika);
        s1.pop();s2.pop();
    }
    return s3;
}
void operator*=(std::stack<int>&s1,int n)
{
    std::stack<int>pom;
    int broj;
    while(!s1.empty())
    {
        broj=s1.top()*n;
        pom.push(broj);
        s1.pop();
    }
    while(!pom.empty())
    {
        s1.push(pom.top());
        pom.pop();
    }
}
bool operator*(const std::stack<int> &s)
{
    bool prazan=1;
    if(s.empty()) prazan=0;
    return prazan;
}
int main()
{
    int niz1[] {1, 5, 7, 3}, niz2[] {1, 9, 0, 4};
    std::stack<int> q1, q2;
    for(auto i : niz1) q1.push(i); // ubacimo elemente
    for(auto i : niz2) q2.push(i); // redoslijed je OBRNUT
    std::cout << q2 << std::endl; // 4 0 9 1 - ispis
    // moraju biti istih dimenzija, inace baciti izuzetak po volji!
    std::cout << q1 - q2<<std::endl; // 0, -4, 7, -1 ispis
    q1 *= 3; // q1 = {9, 21, 15, 3} - redoslijed OBRNUT
    std::cout << q1 << std::endl;
    if(*q1) std::cout << "Nije prazan";
    else std::cout << "Prazan";
    return 0;
}