#include <iostream>
#include <cstdlib>
#include <string>   //for class string
#include <chrono>   //for class system_clock
#include <ctime>    //for the function localtime
using namespace std;

int main()
{
	//A convenient name for each 1 bit.

	const char sun {1 << 0};   //00000001
	const char mon {1 << 1};   //00000010
	const char tue {1 << 2};   //00000100
	const char wed {1 << 3};   //00001000
	const char thu {1 << 4};   //00010000
	const char fri {1 << 5};   //00100000
	const char sat {1 << 6};   //01000000

	struct restaurant {
		string name;
		char days;   //which days of the week the restaurant is open
	};

	//Use "bitwise or" to assemble the individual 1 bits into a byte.

	const restaurant a[] {
		{"Katz's Delicatessen", sun | mon | tue                        }, //00000111 0x07
		{"Tavern on the Green", sun                               | sat}, //01000001 0x41
		{"Wo Hop",              sun | mon | tue | wed | thu | fri | sat}, //01111111 0x7F
		{"Luchow's",                  mon | tue | wed                  }, //00001110 0x0E
		{"Delmonico's",         sun                   | thu | fri      }  //00110001 0x31
	};

	const size_t n {size(a)};   //how many restaurants
	
	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 day {p->tm_wday}; //0 = Sunday, 1 = Monday, ... 6 = Saturday

	const string dayname[] {
		"Sunday",    //0
		"Monday",    //1
		"Tuesday",   //2
		"Wednesday", //3
		"Thursday",  //4
		"Friday",    //5
		"Saturday"   //6
	};

	cout << "Today is " << dayname[day] << ".\n";
	cout << "The following restaurants are open today:\n";

	for (int i {0}; i < n; ++i) {
		//If bit number day of the byte a[i].days is turned on,
		if ((a[i].days >> day) & 0x1) {
			cout << a[i].name << "\n";
		}
	}

	return EXIT_SUCCESS;
}