Taeluf.com

part2

#!/usr/bin/env php
<?php
/**
 * For each game, determine how many cubes are required in each color. Multiply those numbers together to get the 'power' for a game. Sum the 'power' for all games.
 */

//$input = file_get_contents(__DIR__.'/sample.txt');
$input = file_get_contents(__DIR__.'/input.txt');

$game_lines = explode("\n", trim($input));

$total = 0;

foreach ($game_lines as $line){
    $game_parts = explode(": ", $line);
    $rounds_text = $game_parts[1];
    $game_num = explode(" ",$game_parts[0])[1];

    $game_amounts = [];

    $rounds = explode('; ', $rounds_text);
    // each round is like: 1 red, 10 blue, 5 green
    $can_add_game = true;
    foreach ($rounds as $round){
        $results = explode(", ", $round);
        foreach ($results as $result){
            $parts = explode(" ", $result);
            $color = $parts[1];
            $amount = $parts[0];

            if ($amount > ($game_amounts[$color] ?? 0 ))$game_amounts[$color] = $amount;
        }
    }

    $total += ($game_amounts['red'] * $game_amounts['green'] * $game_amounts['blue']);
}

echo "Power of all games: $total\n";