AdventOfCode/AdventOfCode.Solutions/2023/Day 02/Day02.cs

using AdventOfCode.Core.Shared.IO;
using System.Text.RegularExpressions;

namespace AdventOfCode.Solutions._2023
{
    public class Day02: IChallange
    {
        public int Year => 2023;
        public int Day => 2;

        private readonly IInputReader _inputReader;

        public Day02(IInputReader inputReader)
        {
            _inputReader = inputReader;
            _inputReader.SetInput(this);
        }

        public async Task<string> GetSolutionPart1()
        {
            int sum = 0;
            await foreach(string line in _inputReader.ReadAsStringLine())
            {
                // get all the numers
                string gameId = line.Split(':')[0].Split(' ')[1];
                string[] dicePulls = line.Split(':')[1].Split(';');
                bool impossible = false;

                // parse the pulls
                foreach (string dicePull in dicePulls)
                {
                    // regex the pull
                    MatchCollection dice = Regex.Matches(dicePull, "(\\d+) (g|r|b)");
                    foreach (Match match in dice)
                    {
                        string[] splitted = match.Value.Split(' ');
                        int ammount = int.Parse(splitted[0]);

                        if (ammount <= 12) // pass for all dice
                            continue;

                        if (ammount > 14 // fail for any dice set
                            || (splitted[1] == "r" && ammount > 12)
                            || (splitted[1] == "g" && ammount > 13))
                            impossible = true; // not possible

                        if (impossible) break;
                    }

                    if (impossible) break;
                }

                if (!impossible) 
                {
                    sum += int.Parse(gameId);
                }
            }
            return sum.ToString();
        }

        public async Task<string> GetSolutionPart2()
        {
            int sum = 0;
            await foreach (string line in _inputReader.ReadAsStringLine())
            {
                // get all the numers
                string dicePulls = line.Split(':')[1];

                // parse the pulls
                MatchCollection dice = Regex.Matches(dicePulls, "(\\d+) (g|r|b)");
                int red = 0, green = 0, blue = 0;
                foreach (Match match in dice)
                {
                    string[] splitted = match.Value.Split(' ');
                    int ammount = int.Parse(splitted[0]);

                    if (splitted[1] == "r" && ammount > red) { red = ammount; }
                    else if (splitted[1] == "g" && ammount > green) { green = ammount; }
                    else if (splitted[1] == "b" && ammount > blue) { blue = ammount; }
                }


                sum += red * green * blue;
            }
            return sum.ToString();
        }
    }
}