#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <iterator>
#include <map>
#include <vector>
#include <algorithm>

int main(int argc, char *argv[])
{
	if (argc < 3)
	{
		std::cerr << "Not enough arguments" << std::endl;
		return 1;
	}

	std::ifstream f(argv[1]);
	if (f.is_open())
	{
		std::map<std::string, int> m;

		std::stringstream wss;
		wss << f.rdbuf();
		f.close();

		std::string buf = "";

		std::string line = wss.str();
		for (auto it : line)
		{
			if ((it > 64 && it < 91) || (it > 96 && it < 123))
			{
				buf += tolower(it);
			}
			else
			{
				if (buf.length() > 0)
				{
					m[buf]++;
					buf.clear();
				}
			}
		}

		std::vector<std::pair<std::string, int> > v(m.size());

		std::copy(m.begin(), m.end(), v.begin());
		m.clear();

		std::sort
		(
			v.begin(), v.end(),
			[](std::pair<std::string, int> const & a, std::pair<std::string, int> const & b)
			{
				return a.second != b.second ? a.second > b.second : a.first < b.first;
			}
		);

		std::ofstream of(argv[2]);
		if (of.is_open())
		{
			for (std::pair<std::string, int> p : v)
			{
				of << p.second << " " << p.first << std::endl;
			}
			of.close();
		}
		else
		{
			std::cerr << "Can't open file " << argv[2] << std::endl;
			return 1;
		}
	}
	else
	{
		std::cerr << "Can't open file " << argv[1] << std::endl;
		return 1;
	}

    return 0;
}