main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <algorithm>
#include <vector>
#include <intrin.h>

int charToInt(char c)
{
	int t = (int)c;
	if (t > 122) return -1;
	if (t >= 97) return (t - 97);
	if (t > 90) return -1;
	if (t >= 65) return (t - 41);
	return -1;
}

int main(int argc, char* argv[])
{
	//__debugbreak();
	if (argc < 2)
	{
		std::cout << "No file supplied." << std::endl;
		return 1;
	}
	if (argc > 2)
	{
		std::cout << "Too many inputs (quotes needed?)" << std::endl;
		return 1;
	}
	std::ifstream file(argv[1]);
	if (file.is_open())
	{
		/* //Part 1
		int seen[26];
		
		bool twoSame;
		bool threeSame;

		int numTwos = 0;
		int numThrees = 0;
		
		std::string line;
		while (std::getline(file, line))
		{
			for (int i = 0; i < 26; i++) seen[i] = 0;
			twoSame = false;
			threeSame = false;

			for each (char c in line)
			{
				int i = charToInt(c);
				if (i < 0) continue;
				seen[i]++;
			}

			for (int i = 0; i < 26; i++)
			{
				if (seen[i] == 2) twoSame = true;
				if (seen[i] == 3) threeSame = true;
			}

			if (twoSame) numTwos++;
			if (threeSame) numThrees++;
		}

		int checksum = numThrees * numTwos;
		std::cout << "Checksum: " << checksum << std::endl;
		return 0;
		*/

		std::vector<std::string> lines = std::vector<std::string>();
		std::string s;
		while (std::getline(file, s)) lines.push_back(s);
		file.close();
		int nLines = lines.size();
		bool found = false;
		int foundA, foundB;
		for (int i = 0; i < (nLines - 1); i++)
		{
			std::string& iLine = lines[i];

			for (int j = (i + 1); j < nLines; j++)
			{
				std::string& jLine = lines[j];

				int diffs = 0;
				for (int k = 0; k < jLine.length(); k++)
				{
					if (iLine[k] != jLine[k]) diffs++;
				}
				if (diffs == 1)
				{
					found = true;
					foundA = i;
					foundB = j;
					break;
				}

			}
			if (found) break;
		}

		std::string& aLine = lines[foundA];
		std::string& bLine = lines[foundB];
		std::cout << "matching chars: ";
		for (int c = 0; c < aLine.length(); c++)
		{
			if (aLine[c] == bLine[c]) std::cout << aLine[c];
		}
		std::cout << std::endl;

		return 0;

	}
	else
	{
		std::cout << "Failed to open file!" << std::endl;
		return 1;
	}

	std::cout << "An unknown error ocurred!" << std::endl;
	return 1;
}