Countdown timer

countdown.cpp

#include <iostream>
#include <windows.h>

void countdown(int t) {
	int mins = 0, secs = 0, hours = 0;

	printf("\n");
	
	while (t) {
		mins = t / 60;
		secs = t % 60;

		if (mins >= 60) {
			hours = mins / 60;
			mins = mins % 60;
		} else {
			hours = 0;
		}

		printf("%02d:%02d:%02d\r", hours, mins, secs);

		Sleep(1000);
		t--;
	}
}

int main(int argc, char const **argv)
{
	char *endptr;
	long int t = strtol(argv[1], &endptr, 10);
	if ((argc != 2) || (!*argv[1] || *endptr)) {
		printf("\n\tUsage: countdown.exe [sec.]\n");
		return 0;
	}

	countdown(atoi(argv[1]));

	printf("Time's up!\n");
	for (int i =0; i < 3; ++i) {
		Beep(1500, 500);
		Sleep(500);
	}

	return 0;
}