T12 - zad.2.

#include <iostream>
#include <cmath>
#include <stdexcept>
#include <iomanip>

class Sat
{
    int sati, minute, sekunde;
    public:
    Sat(int sati, int minute, int sekunde) { Postavi(sati, minute, sekunde);}
    void Postavi(int sati, int minute, int sekunde);
    int DajSate() const { return sati; };
    int DajMinute() const { return minute; };
    int DajSekunde() const { return sekunde; };
    friend std::ostream &operator << (std::ostream &tok, const Sat& satic);
    Sat &operator+=(int pomak);
    Sat &operator++();
    Sat operator++(int);

};

void Sat::Postavi(int sati, int minute, int sekunde)
{
    if(sekunde>=60 || minute>=60 || sati>24)
        throw std::domain_error("Neispravan unos");
    this->sati=sati; this->minute=minute; this->sekunde=sekunde;
}

std::ostream &operator <<(std::ostream &tok, const Sat& satic){
        tok << std::setw(2) << std::setfill('0')<<satic.sati<<":"
            << std::setw(2) << std::setfill('0')<<satic.minute<<":"
            <<std::setw(2) << std::setfill('0')<<satic.sekunde<<std::endl;}

Sat &Sat::operator+=(int pomak)
{
    sekunde+=pomak;
    if (sekunde>59) while(sekunde>59) {sekunde-=60; minute++;}
    if (minute>59) while(minute>59) {minute-=60; sati++;}
    if (sati>23) sati=0;
    return *this;
}

Sat &Sat::operator++()
{
    sekunde++;
    if (sekunde>59) while(sekunde>59) {sekunde-=60; minute++;}
    if (minute>59) while(minute>59) {minute-=60; sati++;}
    if (sati>23) sati=0;
    return *this;
}

Sat Sat::operator++(int)
{
    Sat pomocni(*this);
    sekunde++;
    if (sekunde>59) while(sekunde>59) {sekunde-=60; minute++;}
    if (minute>59) while(minute>59) {minute-=60; sati++;}
    if (sati>23) sati=0;
    return pomocni;
}

int main(){
Sat satic(23,59,59); std::cout<<satic;
satic+=1; std::cout<<satic;
satic++; std::cout<<satic;
++satic+=1; std::cout<<satic++;
std::cout<<satic;
}