thomas_2022/day_2/main2.cpp

#include <utility>
#include <iostream>
#include <fstream>
#include <vector>


enum class Play : int {
    ROCK = 1,
    PAPER = 2,
    SCISSORS = 3,
};

enum class Result : char {
    WIN = 'W',
    LOSS = 'L',
    TIE = 'T',
};


typedef std::pair<Play, Result> game_t;


Play char_to_play(char c) {
    switch(c) {
        case 'A':
            return Play::ROCK;
        case 'B':
            return Play::PAPER;
        case 'C':
            return Play::SCISSORS;
    }
    throw;
}

Result char_to_result(char c) {
    switch(c) {
        case 'X':
            return Result::LOSS;
        case 'Y':
            return Result::TIE;
        case 'Z':
            return Result::WIN;
    }
    throw;
}

Play cheat(Play opponent, Result result) {
    if(result == Result::WIN) {
        if(opponent == Play::ROCK)     return Play::PAPER;
        if(opponent == Play::PAPER)    return Play::SCISSORS;
        if(opponent == Play::SCISSORS) return Play::ROCK;
    } else if(result == Result::LOSS) {
        if(opponent == Play::ROCK)     return Play::SCISSORS;
        if(opponent == Play::PAPER)    return Play::ROCK;
        if(opponent == Play::SCISSORS) return Play::PAPER;
    } else {
        return opponent;
    }
    throw;
}


std::vector<game_t> read_file(std::string path) {
    std::fstream file;
    file.open(path);

    std::string line;
    std::vector<game_t> games;
    while(file) {
        std::getline(file, line);
        if(line == "")
            break;

        auto opponent = char_to_play(line[0]);
        auto mine = char_to_result(line[2]);

        games.push_back(std::make_pair(opponent, mine));
    }

    return games;
}


int score_game(Play play, Result result) {
    int score = 0;
    if(result == Result::WIN)
        score = 6;
    else if(result == Result::TIE)
        score = 3;

    score += (int)play;

    return score;
}


int main(int argc, char *argv[]) {
    auto games = read_file(argv[1]);

    int total = 0;

    for(auto game : games) {
        auto [opponent, result] = game;

        auto me = cheat(opponent, result);

        std::cout << (int)opponent << " " << (int)me << std::endl;
        int score = score_game(me, result);
        std::cout << score << std::endl;
        total += score;
    }

    std::cout << total << std::endl;

    return 0;
}