Meeting Schedules

meeting-schedules.cpp

#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>

using namespace std;

void print_timespan(int start_time, int end_time)
{
	if (start_time - 1 > 0) start_time--;

	int start_hour = start_time / 60;
	int start_minute = start_time - start_hour * 60;

	int end_hour = end_time / 60;
	int end_minute = end_time - end_hour * 60;

	if (start_hour == 24) start_hour = 0;
	if (end_hour == 24) end_hour = 0;

	cout << setfill('0') << setw(2) << start_hour << " "
		 << setfill('0') << setw(2) << start_minute << " " 
		 << setfill('0') << setw(2) << end_hour << " " 
		 << setfill('0') << setw(2) << end_minute
		 << endl;
}

int main()
{
	int number, meeting_timespan;
	cin >> number >> meeting_timespan;

	vector<bool> schedule(1440, true);

	for (int i = 0; i < number; ++i)
	{
		int hour1, minutes1, hour2, minutes2;
		cin >> hour1 >> minutes1 >> hour2 >> minutes2;

		int start_time = hour1 * 60 + minutes1;
		int end_time = hour2 * 60 + minutes2;

		for (int i = start_time; i <= end_time; ++i)
		{
			schedule[i] = false;
		}
	}

	int head = 0;
	int tail = 0;

	//cout << endl;

	while (head < schedule.size())
	{
		tail = distance(schedule.begin(), find(schedule.begin() + head, schedule.end(), false));

		int length = tail - head + 1;
		if (length >= meeting_timespan)
		{
			print_timespan(head, tail);
		}

		head = distance(schedule.begin(), find(schedule.begin() + tail, schedule.end(), true));
	}	
	
	return 0;
}