#include <iostream>
#include <iomanip> //for the i/o manipulator setprecision
#include <cstdlib>
#include <chrono>  //for class system_clock
#include <ctime>   //for the function localtime and structure tm
using namespace std;

int main()
{
	const auto now {chrono::system_clock::now()};
	const time_t t {chrono::system_clock::to_time_t(now)};
        const tm *const p {localtime(&t)};

	const int weekday {p->tm_wday}; //0 = Sun, 1 = Mon, 2 = Tue, etc.

	double price1;
	if (weekday == 0) {
		price1 = 30.00; //Haircut more expensive on Sundays.
	} else {
		price1 = 20.00; //Haircut less expensive on other days.
	}

	//Another way to do the same thing.
	//This time, the price can be const.
	const double price2 {weekday == 0 ? 30.00 : 20.00};

	cout << "$" << fixed << setprecision(2) << price1 << "\n";
	cout << "$" << fixed << setprecision(2) << price2 << "\n";

	return EXIT_SUCCESS;
}