#include <fstream>
#include <iostream>
#include <set>
#include <string>
#include <vector>

int score(char c)
{
	if(c >= 'a' && c <= 'z')
		return (c - 'a') + 1;
	return (c - 'A') + 1 + 26;
}

int main()
{
	std::ifstream ifs("data.txt");
	if(!ifs.is_open())
	{
		std::cerr << "Missing data.txt." << std::endl;
		return -1;
	}

	unsigned long total = 0;
	unsigned long total_pt2 = 0;

	for(std::string line; std::getline(ifs, line); )
	{
		if(line == "")
			continue;

		const size_t half = line.size() / 2;
		std::string right = line.substr(half);
		for(int i = 0; i < half; ++i)
		{
			if(right.contains(line[i]))
			{
				total += score(line[i]);
				break;
			}
		}

		// Part 2:
		static std::vector<std::string> lines;
		lines.push_back(line);
		if(lines.size() == 3)
		{
			// get all letters it could be from first line
			std::set<char> options;
			for(const char c : lines[0])
				options.insert(c);

			// remove if not a duplicate
			std::set<char> to_remove;
			for(auto i = 1; i < 3; ++i) // remaining two lines
			{
				for(const char c : options)
					if(!lines[i].contains(c))
						to_remove.insert(c);
				for(const char c : to_remove)
					options.erase(c);
			}

			if(options.size() != 1)
			{
				std::cerr << "Error: More than one remaining option: ";
				for(const char c : options)
					std::cout << c << ",";
				exit(-1);
			}

			total_pt2 += score(*(options.begin()));

			lines.clear(); // reset
		}
	}

	std::cout << "    Total: " <<     total << std::endl;
	std::cout << "PT2 Total: " << total_pt2 << std::endl;

	return 0;
}