Found a C per-char solution, that is, no lines, splitting, lookahead, etc. It wasn't even necessary to keep match lengths for the color names because they all have unique characters, e.g. 'b' only occurs in "blue" so then you can attribute the count to that color.

int main()
{
	int p1=0,p2=0, id=1,num=0, r=0,g=0,b=0, c;

	while ((c = getchar()) != EOF)
		if (c==',' || c==';' || c==':') num = 0; else
		if (c>='0' && c<='9') num = num*10 + c-'0'; else
		if (c=='d') r = MAX(r, num); else
		if (c=='g') g = MAX(g, num); else
		if (c=='b') b = MAX(b, num); else
		if (c=='\n') {
			p1 += (r<=12 && g<=13 && b<=14) * id;
			p2 += r*g*b;
			r=g=b=0; id++;
		}

	printf("%d %d\n", p1, p2);
	return 0;
}

Golfed:

c,p,P,i,n,r,g,b;main(){while(~
(c=getchar()))c==44|c==58|59==
c?n=0:c>47&c<58?n=n*10+c-48:98
==c?b=b>n?b:n:c=='d'?r=r>n?r:n
:c=='g'?g=g>n?g:n:10==c?p+=++i
*(r<13&g<14&b<15),P+=r*g*b,r=g
=b=0:0;printf("%d %d\n",p,P);}

Rust

Pretty straightforward this time, the bulk of the work was clearly in parsing the input.

Not too tricky today. Part 2 wasn't as big of a curveball as yesterday thankfully. I don't think it's the cleanest code I've ever written, but hey - the whole point of this is to get better at Rust, so I'll definitely be learning as I go, and coming back at the end to clean a lot of these up. I think for this one I'd like to look into a parsing crate like nom to clean up all the spliting and unwrapping in the two from() methods.

https://github.com/capitalpb/advent_of_code_2023/blob/main/src/solvers/day02.rs

#[derive(Debug)]
struct Hand {
    blue: usize,
    green: usize,
    red: usize,
}

impl Hand {
    fn from(input: &str) -> Hand {
        let mut hand = Hand {
            blue: 0,
            green: 0,
            red: 0,
        };

        for color in input.split(", ") {
            let color = color.split_once(' ').unwrap();
            match color.1 {
                "blue" => hand.blue = color.0.parse::().unwrap(),
                "green" => hand.green = color.0.parse::().unwrap(),
                "red" => hand.red = color.0.parse::().unwrap(),
                _ => unreachable!("malformed input"),
            }
        }

        hand
    }
}

#[derive(Debug)]
struct Game {
    id: usize,
    hands: Vec,
}

impl Game {
    fn from(input: &str) -> Game {
        let (id, hands) = input.split_once(": ").unwrap();
        let id = id.split_once(" ").unwrap().1.parse::().unwrap();
        let hands = hands.split("; ").map(Hand::from).collect();
        Game { id, hands }
    }
}

pub struct Day02;

impl Solver for Day02 {
    fn star_one(&self, input: &str) -> String {
        input
            .lines()
            .map(Game::from)
            .filter(|game| {
                game.hands
                    .iter()
                    .all(|hand| hand.blue <= 14 && hand.green <= 13 && hand.red <= 12)
            })
            .map(|game| game.id)
            .sum::()
            .to_string()
    }

    fn star_two(&self, input: &str) -> String {
        input
            .lines()
            .map(Game::from)
            .map(|game| {
                let max_blue = game.hands.iter().map(|hand| hand.blue).max().unwrap();
                let max_green = game.hands.iter().map(|hand| hand.green).max().unwrap();
                let max_red = game.hands.iter().map(|hand| hand.red).max().unwrap();

                max_blue * max_green * max_red
            })
            .sum::()
            .to_string()
    }
}

This was mostly straightforward... basically just parsing input. Here are my condensed solutions in Python

Game = dict[str, int]

RED_MAX   = 12
GREEN_MAX = 13
BLUE_MAX  = 14

def read_game(stream=sys.stdin) -> Game:
    try:
        game_string, cubes_string = stream.readline().split(':')
    except ValueError:
        return {}

    game: Game = defaultdict(int)
    game['id'] = int(game_string.split()[-1])

    for cubes in cubes_string.split(';'):
        for cube in cubes.split(','):
            count, color = cube.split()
            game[color] = max(game[color], int(count))

    return game

def read_games(stream=sys.stdin) -> Iterator[Game]:
    while game := read_game(stream):
        yield game

def is_valid_game(game: Game) -> bool:
    return all([
        game['red']   <= RED_MAX,
        game['green'] <= GREEN_MAX,
        game['blue']  <= BLUE_MAX,
    ])

def main(stream=sys.stdin) -> None:
    valid_games = filter(is_valid_game, read_games(stream))
    sum_of_ids  = sum(game['id'] for game in valid_games)
    print(sum_of_ids)

def power(game: Game) -> int:
    return game['red'] * game['green'] * game['blue']

def main(stream=sys.stdin) -> None:
    sum_of_sets = sum(power(game) for game in read_games(stream))
    print(sum_of_sets)

GitHub Repo

Ruby

https://github.com/snowe2010/advent-of-code/blob/master/ruby_aoc/2023/day02/day02.rb

Second part was soooo much easier today than yesterday. Helps I solved it exactly how he wanted you to solve it I think.

I'm going to work on some code golf now.

Golfed P2 down to 133 characters:

p g.map{_1.sub!(/.*:/,'')
m=Hash.new(0)
_1.split(?;){|r|r.split(?,){|a|b,c=a.split
m[c]=[m[c],b.to_i].max}}
m.values.reduce(&:*)}.sum

I had some time, so here's a terrible solution in Uiua (Run it here) :

Lim ← [14 13 12]
{"Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green"
 "Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue"
 "Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red"
 "Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red"
 "Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green"}

LtoDec ← ∧(+ ×10:) :0
StoDec ← LtoDec▽≥0. ▽≤9. -@0
FilterMax! ← /↥≡(StoDec⊢↙ ¯1)⊔⊏⊚≡(/×^1⊢).⊔
# Build 'map' of draws for each game
∵(□≡(∵(⬚@\s↙2 ⊔) ⇌) ↯¯1_2 ↘ 2⊜□≠@\s . ⊔)
# Only need the max for each colour
≡(⊂⊂⊃⊃(FilterMax!(="bl")) (FilterMax!(="gr")) (FilterMax!(="re")))
# part 1 - Compare against limits, and sum game numbers
/+▽:+1⇡⧻. ≡(/×≤0-Lim).
# part 2 - Multiply the maxes in each game and then sum.
/+/×⍉:

Factor on github (with comments and imports):

: known-color ( color-phrases regexp -- n )
  all-matching-subseqs [ 0 ] [
    [ split-words first string>number ] map-supremum
  ] if-empty
;

: line>known-rgb ( str -- game-id known-rgb )
  ": " split1 [ split-words last string>number ] dip
  R/ \d+ red/ R/ \d+ green/ R/ \d+ blue/
  [ known-color ] tri-curry@ tri 3array
;

: possible? ( known-rgb test-rgb -- ? )
  v<= [ ] all?
;

: part1 ( -- )
  "vocab:aoc-2023/day02/input.txt" utf8 file-lines
  [ line>known-rgb 2array ]
  [ last { 12 13 14 } possible? ] map-filter
  [ first ] map-sum .
;

: part2 ( -- )
  "vocab:aoc-2023/day02/input.txt" utf8 file-lines
  [ line>known-rgb nip product ] map-sum .
;

Mostly an input parsing problem this time, but it was fun to use Hares tokenizer functions:

-- SPDX-FileCopyrightText: 2023 Jummit
--
-- SPDX-License-Identifier: GPL-3.0-or-later

local colors = {"blue", "red", "green"}
local available = {red = 12, blue = 14, green = 13}
local possible = 0
local id = 0
local min = 0

for game in io.open("2.input"):lines() do
  id = id + 1
  game = game:gsub("Game %d+: ", "").."; "
  local max = {red = 0, blue = 0, green = 0}
  for show in game:gmatch(".-; ") do
    for _, color in ipairs(colors) do
      local num = tonumber(show:match("(%d+) "..color))
      if num then
        max[color] = math.max(max[color], num)
      end
    end
  end
  min = min + max.red * max.blue * max.green
  local thisPossible = true
  for _, color in ipairs(colors) do
    if max[color] > available[color] then
      thisPossible = false
      break
    end
  end
  if thisPossible then
    possible = possible + id
  end
end

print(possible)
print(min)

// SPDX-FileCopyrightText: 2023 Jummit
//
// SPDX-License-Identifier: GPL-3.0-or-later

use strconv;
use types;
use strings;
use io;
use bufio;
use os;
use fmt;

const available: []uint = [12, 13, 14];

fn color_id(color: str) const uint = {
	switch (color) {
	case "red" => return 0;
	case "green" => return 1;
	case "blue" => return 2;
	case => abort();
	};
};

export fn main() void = {
	const file = os::open("2.input")!;
	defer io::close(file)!;
	const scan = bufio::newscanner(file, types::SIZE_MAX);
	let possible: uint = 0;
	let min: uint = 0;

	for (let id = 1u; true; id += 1) {
		const line = match(bufio::scan_line(&scan)!) {
		case io::EOF =>
			break;
		case let line: const str =>
			yield strings::sub(
					line,
					strings::index(line, ": ") as size + 2,
					strings::end);
		};
		let max: []uint = [0, 0, 0];
		let tok = strings::rtokenize(line, "; ");
		for (true) {
			const show = match(strings::next_token(&tok)) {
			case void =>
				break;
			case let show: str =>
				yield show;
			};
			const pairs = strings::tokenize(show, ", ");
			for (true) {
				const pair: (str, str) = match(strings::next_token(&pairs)) {
				case void =>
					break;
				case let pair: str =>
					let tok = strings::tokenize(pair, " ");
					yield (
						strings::next_token(&tok) as str,
						strings::next_token(&tok) as str
					);
				};
				let color = color_id(pair.1);
				let amount = strconv::stou(pair.0)!;
				if (amount > max[color]) max[color] = amount;
			};
		};
		if (max[0] <= available[0] && max[1] <= available[1] && max[2] <= available[2]) {
			fmt::printfln("{}", id)!;
			possible += id;
		};
		min += max[0] * max[1] * max[2];
	};
	
	fmt::printfln("{}", possible)!;
	fmt::printfln("{}", min)!;
};

Rust (Rank 7421/6311) (Time after start 00:32:27/00:35:35)

Extremely easy part 2 today, I would say easier than part 1 but they share the same sort of framework

use std::fs;

fn part1(input: String) -> i32 {
    const RED: i32 = 12;
    const GREEN: i32 = 13;
    const BLUE: i32 = 14;

    let mut sum = 0;

    for line in input.lines() {
        let [id, content] = line.split(": ").collect::>()[0..2] else { continue };
        let id = id.split(" ").collect::>()[1].parse::().unwrap();

        let marbles = content.split("; ").map(|x| { x.split(", ").collect::>() }).collect::>>();
        let mut valid = true;

        for selection in marbles {
            for marble in selection {
                let marble_split = marble.split(" ").collect::>();
                let marble_amount = marble_split[0].parse::().unwrap();
                let marble_color = marble_split[1];

                if marble_color == "red" && marble_amount > RED {
                    valid = false;
                    break;
                }

                if marble_color == "green" && marble_amount > GREEN {
                    valid = false;
                    break;
                }

                if marble_color == "blue" && marble_amount > BLUE {
                    valid = false;
                    break;
                }
            }
        }

        if !valid {
            continue;
        }

        sum += id;
    }

    return sum;
}

fn part2(input: String) -> i32 {
    let mut sum = 0;

    for line in input.lines() {
        let [id, content] = line.split(": ").collect::>()[0..2] else { continue };
        let id = id.split(" ").collect::>()[1].parse::().unwrap();

        let marbles = content.split("; ").map(|x| { x.split(", ").collect::>() }).collect::>>();
        
        let mut red = 0;
        let mut green = 0;
        let mut blue = 0;

        for selection in marbles {
            for marble in selection {
                let marble_split = marble.split(" ").collect::>();
                let marble_amount = marble_split[0].parse::().unwrap();
                let marble_color = marble_split[1];

                if marble_color == "red" && marble_amount > red {
                    red = marble_amount;
                }

                if marble_color == "green" && marble_amount > green {
                    green = marble_amount;
                }

                if marble_color == "blue" && marble_amount > blue {
                    blue = marble_amount;
                }
            }
        }

        sum += red * green * blue;
    }

    return sum;
}

fn main() {
    let input = fs::read_to_string("data/input.txt").unwrap();

    println!("{}", part1(input.clone()));
    println!("{}", part2(input.clone()));
}

Code Link

String parsing! Always fun in C!

https://github.com/sjmulder/aoc/blob/master/2023/c/day02.c

int main(int argc, char **argv)
{
	char ln[256], *sr,*srd,*s;
	int p1=0,p2=0, id, r,g,b;

	for (id=1; (sr = fgets(ln, sizeof(ln), stdin)); id++) {
		strsep(&sr, ":");
		r = g = b = 0;

		while ((srd = strsep(&sr, ";")))
		while ((s = strsep(&srd, ",")))
			if (strchr(s, 'd')) r = MAX(r, atoi(s)); else
			if (strchr(s, 'g')) g = MAX(g, atoi(s)); else
			if (strchr(s, 'b')) b = MAX(b, atoi(s));
	
		p1 += (r <= 12 && g <= 13 && b <= 14) * id;
		p2 += r * g * b;
	}

	printf("%d %d\n", p1, p2);
	return 0;
}

Dart solution

Quite straightforward, though there's a sneaky trap in the test data for those of us who don't read the rules carefully enough.

Read, run and edit this solution in your browser: https://dartpad.dev/?id=203b3f0a9a1ad7a51daf14a1aeb6cf67

parseLine(String s) {
  var game = s.split(': ');
  var num = int.parse(game.first.split(' ').last);
  var rounds = game.last.split('; ');
  var cubes = [
    for (var (e) in rounds)
      {
        for (var ee in e.split(', '))
          ee.split(' ').last: int.parse(ee.split(' ').first)
      }
  ];
  return MapEntry(num, cubes);
}

/// collects the max of the counts from both maps.
Map merge2(Map a, Map b) => {
      for (var k in {...a.keys, ...b.keys}) k: max(a[k] ?? 0, b[k] ?? 0)
    };

var limit = {"red": 12, "green": 13, "blue": 14};

bool isGood(Map test) =>
    limit.entries.every((e) => (test[e.key] ?? 0) <= e.value);

part1(List lines) => lines
    .map(parseLine)
    .where((e) => e.value.every(isGood))
    .map((e) => e.key)
    .sum;

part2(List lines) => lines
    .map(parseLine)
    .map((e) => e.value.reduce(merge2))
    .map((e) => e.values.reduce((s, t) => s * t))
    .sum;

My (awful) Python solves. Much easier than day 1's, although I did run into an issue with trimming whitespace characters with my approach (Game 96 wouldn't flag properly).

with open('02A_input.txt', 'r') as file:
    data = file.readlines()
    
possibleGames=[]

for game in data:
    # Find Game number
    game = game.removeprefix("Game ")
    gameNumber = int(game[0:game.find(":")])
    # Break Game into rounds (split using semicolons)
    game=game[game.find(":")+1:]
    rounds=game.split(";")
    # For each round, determine the maximum number of Red, Blue, Green items shown at a time
    rgb=[0,0,0]
    for round in rounds:
        combos=round.split(",")
        for combo in combos:
            combo=combo.strip()
            number=int(combo[0:combo.find(" ")])
            if combo.endswith("red"):
                if number>rgb[0]:
                    rgb[0]=number
            elif combo.endswith("green"):
                if number>rgb[1]:
                    rgb[1]=number
            elif combo.endswith("blue"):
                if number>rgb[2]:
                    rgb[2]=number
    # If Red>12, Green>13, Blue>14, append Game number to possibleGames
    if not (rgb[0]>12 or rgb[1]>13 or rgb[2]>14):
        possibleGames.append(gameNumber)

print(sum(possibleGames))

with open('02A_input.txt', 'r') as file:
    data = file.readlines()
    
powers=[]

for game in data:
    # Find Game number
    game = game.removeprefix("Game ")
    # Break Game into rounds (split using semicolons)
    game=game[game.find(":")+1:]
    rounds=game.split(";")
    # For each round, determine the maximum number of Red, Blue, Green items shown at a time
    # Note: This could be faster, since we don't need to worry about actual rounds
    rgb=[0,0,0]
    for round in rounds:
        combos=round.split(",")
        for combo in combos:
            combo=combo.strip()
            number=int(combo[0:combo.find(" ")])
            if combo.endswith("red"):
                if number>rgb[0]:
                    rgb[0]=number
            elif combo.endswith("green"):
                if number>rgb[1]:
                    rgb[1]=number
            elif combo.endswith("blue"):
                if number>rgb[2]:
                    rgb[2]=number
    # Multiple R, G, B to find the "power" of the game
    # Append Power to the list
    powers.append(rgb[0]*rgb[1]*rgb[2])
    
print(sum(powers))

Was pretty simple in Python with a regex to get the game number, and then the count of color. for part 2 instead of returning true/false whether the game is valid, you just max the count per color. No traps like in the first one, that I've seen, so it was surprisingly easy

def process_game(line: str):
    game_id = int(re.findall(r'game (\d+)*', line)[0])

    colon_idx = line.index(":")
    draws = line[colon_idx+1:].split(";")
    # print(draws)
    
    if is_game_valid(draws):
        # print("Game %d is possible"%game_id)
        return game_id
    return 0

            
def is_game_valid(draws: list):
    for draw in draws:
        red = get_nr_of_in_draw(draw, 'red')
        if red > MAX_RED:
            return False
        
        green = get_nr_of_in_draw(draw, 'green')
        if green > MAX_GREEN:
            return False
        
        blue = get_nr_of_in_draw(draw, 'blue')
        if blue > MAX_BLUE:
            return False    
    return True
        
            
def get_nr_of_in_draw(draw: str, color: str):
    if color in draw:
        nr = re.findall(r'(\d+) '+color, draw)
        return int(nr[0])
    return 0


# f = open("input.txt", "r")
f = open("input_real.txt", "r")
lines = f.readlines()
sum = 0
for line in lines:
    sum += process_game(line.strip().lower())
print("Answer: %d"%sum)

Done in C# Input parsing done with a mixture of splits and Regex (no idea why everyone hates it?) capture groups.

I have overbuilt for both days, but not tripped on any of the 'traps' in the input data - generally expecting the input to be worse than it is... too used to actual data from users

    public Day2RoundInput(string gameString)
    {
        var colonSplit = gameString.Trim().Split(':', StringSplitOptions.RemoveEmptyEntries);
        var match = gameNumRegex.Match(colonSplit[0].Trim());
        var gameNumberString = match.Groups[1].Value;
        GameNumber = int.Parse(gameNumberString.Trim());

        HandfulsOfCubes = new List();
        var roundsSplit = colonSplit[1].Trim().Split(';', StringSplitOptions.RemoveEmptyEntries);
        foreach (var round in roundsSplit)
        {
            HandfulsOfCubes.Add(new HandfulCubes(round));
        }
    }
    public int GameNumber { get; set; }

    public List HandfulsOfCubes { get; set; }

    public class HandfulCubes
    {
        private Regex colourRegex = new Regex("([0-9]*) (red|green|blue)");

        public HandfulCubes(string roundString)
        {
            var colourCounts = roundString.Split(',', StringSplitOptions.RemoveEmptyEntries);
            foreach (var colour in colourCounts)
            {
                var matches = colourRegex.Matches(colour.Trim());

                foreach (Match match in matches)
                {
                    var captureOne = match.Groups[1];

                    var count = int.Parse(captureOne.Value.Trim());

                    var captureTwo = match.Groups[2];

                    switch (captureTwo.Value.Trim().ToLower())
                    {
                        case "red":
                            RedCount = count;
                            break;
                        case "green":
                            GreenCount = count;
                            break;
                        case "blue":
                            BlueCount = count;
                            break;
                        default: throw new Exception("uh oh");
                    }
                }
            }
        }

        public int RedCount { get; set; }
        public int GreenCount { get; set; }
        public int BlueCount { get; set; }
    }

}

        var maxAllowedRed = 12;
        var maxAllowedGreen = 13;
        var maxAllowedBlue = 14;

        var allowedGameIdSum = 0;

        foreach ( var game in inputs ) { 
            var maxRed = game.HandfulsOfCubes.Select(h => h.RedCount).Max();
            var maxGreen = game.HandfulsOfCubes.Select(h => h.GreenCount).Max();
            var maxBlue = game.HandfulsOfCubes.Select(h => h.BlueCount).Max();

            if ( maxRed <= maxAllowedRed && maxGreen <= maxAllowedGreen && maxBlue <= maxAllowedBlue) 
            {
                allowedGameIdSum += game.GameNumber;
                Console.WriteLine("Game:" + game.GameNumber + " allowed");
            }
            else
            {
                Console.WriteLine("Game:" + game.GameNumber + "not allowed");
            }
        }

        Console.WriteLine("Sum:" + allowedGameIdSum.ToString());

    }

    private List GetInputs()
    {
        List inputs = new List();

        var textLines = File.ReadAllLines("Days/Two/Day2Input.txt");

        foreach (var line in textLines)
        {
            inputs.Add(new Day2RoundInput(line));
        }

        return inputs;
    }

    
}

        var result = 0;

        foreach ( var game in inputs ) {
            var maxRed = game.HandfulsOfCubes.Select(h => h.RedCount).Max();
            var maxGreen = game.HandfulsOfCubes.Select(h => h.GreenCount).Max();
            var maxBlue = game.HandfulsOfCubes.Select(h => h.BlueCount).Max();

            var power = maxRed*maxGreen*maxBlue;
            Console.WriteLine("Game:" + game.GameNumber + " Result:" + power.ToString());

            result += power;
        }

        Console.WriteLine("Day2 Task2 Result:" + result.ToString());

    }

    private List GetInputs()
    {
        List inputs = new List();

        var textLines = File.ReadAllLines("Days/Two/Day2Input.txt");
        //var textLines = File.ReadAllLines("Days/Two/Day2ExampleInput.txt");

        foreach (var line in textLines)
        {
            inputs.Add(new Day2RoundInput(line));
        }

        return inputs;
    }

    
}

C# - a tad bit overkill for this. I was worried that we'd need more statistical analysis in part 2, so I designed my solution around that. I ended up cutting everything back when Max() was enough for both parts.

https://github.com/warriordog/advent-of-code-2023/tree/main/Solutions/Day02

A solution in Nim language. Pretty straightforward code. Most logic is just parsing input + a bit of functional utils: allIt checks if all items in a list within limits to check if game is possible and mapIt collects red, green, blue cubes from each set of game.

https://codeberg.org/Archargelod/aoc23-nim/src/branch/master/day_02/solution.nim

import std/[strutils, strformat, sequtils]

type AOCSolution[T] = tuple[part1: T, part2: T]

type
  GameSet = object
    red, green, blue: int
  Game = object
    id: int
    sets: seq[GameSet]

const MaxSet = GameSet(red: 12, green: 13, blue: 14)

func parseGame(input: string): Game =
  result.id = input.split({':', ' '})[1].parseInt()
  let sets = input.split(": ")[1].split("; ").mapIt(it.split(", "))
  for gSet in sets:
    var gs = GameSet()
    for pair in gSet:
      let
        pair = pair.split()
        cCount = pair[0].parseInt
        cName = pair[1]

      case cName:
      of "red":
        gs.red = cCount
      of "green":
        gs.green = cCount
      of "blue":
        gs.blue = cCount

    result.sets.add gs

func isPossible(g: Game): bool =
  g.sets.allIt(
    it.red <= MaxSet.red and
    it.green <= MaxSet.green and
    it.blue <= MaxSet.blue
  )


func solve(lines: seq[string]): AOCSolution[int]=
  for line in lines:
    let game = line.parseGame()

    block p1:
      if game.isPossible():
        result.part1 += game.id

    block p2:
      let
        minRed = game.sets.mapIt(it.red).max()
        minGreen = game.sets.mapIt(it.green).max()
        minBlue = game.sets.mapIt(it.blue).max()

      result.part2 += minRed * minGreen * minBlue


when isMainModule:
  let input = readFile("./input.txt").strip()
  let (part1, part2) = solve(input.splitLines())

  echo &"Part 1: The sum of valid game IDs equals {part1}."
  echo &"Part 2: The sum of the sets' powers equals {part2}."

Did mine in Odin. Found this day's to be super easy, most of the challenge was just parsing.

package day2

import "core:fmt"
import "core:strings"
import "core:strconv"
import "core:unicode"

Round :: struct {
    red: int,
    green: int,
    blue: int,
}

parse_round :: proc(s: string) -> Round {
    ret: Round

    rest := s
    for {
        nextNumAt := strings.index_proc(rest, unicode.is_digit)
        if nextNumAt == -1 do break
        rest = rest[nextNumAt:]

        numlen: int
        num, ok := strconv.parse_int(rest, 10, &numlen)
        rest = rest[numlen+len(" "):]

        if rest[:3] == "red" {
            ret.red = num
        } else if rest[:4] == "blue" {
            ret.blue = num
        } else if rest[:5] == "green" {
            ret.green = num
        }
    }

    return ret
}

Game :: struct {
    id: int,
    rounds: [dynamic]Round,
}

parse_game :: proc(s: string) -> Game {
    ret: Game

    rest := s[len("Game "):]

    idOk: bool
    idLen: int
    ret.id, idOk = strconv.parse_int(rest, 10, &idLen)
    rest = rest[idLen+len(": "):]

    for len(rest) > 0 {
        endOfRound := strings.index_rune(rest, ';')
        if endOfRound == -1 do endOfRound = len(rest)

        append(&ret.rounds, parse_round(rest[:endOfRound]))
        rest = rest[min(endOfRound+1, len(rest)):]
    }

    return ret
}

is_game_possible :: proc(game: Game) -> bool {
    for round in game.rounds {
        if round.red   > 12 ||
           round.green > 13 ||
           round.blue  > 14 {
            return false
        }
    }
    return true
}

p1 :: proc(input: []string) {
    totalIds := 0

    for line in input {
        game := parse_game(line)
        defer delete(game.rounds)

        if is_game_possible(game) do totalIds += game.id
    }

    fmt.println(totalIds)
}

p2 :: proc(input: []string) {
    totalPower := 0

    for line in input {
        game := parse_game(line)
        defer delete(game.rounds)

        minRed   := 0
        minGreen := 0
        minBlue  := 0
        for round in game.rounds {
            minRed   = max(minRed  , round.red  )
            minGreen = max(minGreen, round.green)
            minBlue  = max(minBlue , round.blue )
        }

        totalPower += minRed * minGreen * minBlue
    }

    fmt.println(totalPower)
}

Getting my head around parsing tricks for python, maybe abusing dicts as a replacement for a types, but appears to be working: https://gist.github.com/purplemonkeymad/983eec7ff0629e8834163b17ec673958

Today in Zig

Spent most of the time running down annoying typos in the tokenizer.

Late as always, as I'm on UK time and can't work on these until late evening.

Part 01 and Part 02 in Rust 🦀 :

use std::{
    env, fs,
    io::{self, BufRead, BufReader},
};

#[derive(Debug)]
struct Sample {
    r: u32,
    g: u32,
    b: u32,
}

fn split_cube_set(set: &[&str], colour: &str) -> Option {
    match set.iter().find(|x| x.ends_with(colour)) {
        Some(item) => item
            .trim()
            .split(' ')
            .next()
            .expect("Found item is present")
            .parse::()
            .ok(),
        None => None,
    }
}

fn main() -> io::Result<()> {
    let args: Vec = env::args().collect();
    let filename = &args[1];
    let file = fs::File::open(filename)?;
    let reader = BufReader::new(file);
    let mut valid_game_ids_sum = 0;
    let mut game_power_sum = 0;
    let max_r = 12;
    let max_g = 13;
    let max_b = 14;
    for line_result in reader.lines() {
        let mut valid_game = true;
        let line = line_result.unwrap();
        let line_split: Vec<_> = line.split(':').collect();
        let game_id = line_split[0]
            .split(' ')
            .collect::>()
            .last()
            .expect("item exists")
            .parse::()
            .expect("is a number");
        let rest = line_split[1];
        let cube_sets = rest.split(';');
        let samples: Vec = cube_sets
            .map(|set| {
                let set_split: Vec<_> = set.split(',').collect();
                let r = split_cube_set(&set_split, "red").unwrap_or(0);
                let g = split_cube_set(&set_split, "green").unwrap_or(0);
                let b = split_cube_set(&set_split, "blue").unwrap_or(0);
                Sample { r, g, b }
            })
            .collect();
        let mut highest_r = 0;
        let mut highest_g = 0;
        let mut highest_b = 0;
        for sample in &samples {
            if !(sample.r <= max_r && sample.g <= max_g && sample.b <= max_b) {
                valid_game = false;
            }
            highest_r = u32::max(highest_r, sample.r);
            highest_g = u32::max(highest_g, sample.g);
            highest_b = u32::max(highest_b, sample.b);
        }
        if valid_game {
            valid_game_ids_sum += game_id;
        }
        game_power_sum += highest_r * highest_g * highest_b;
    }
    println!("Sum of game ids: {valid_game_ids_sum}");
    println!("Sum of game powers: {game_power_sum}");
    Ok(())
}

My solutions in C: https://git.sr.ht/~aidenisik/aoc23/tree/master/item/day2

Most of this is just reading the data, surely there's a better way to do this lol.

Python, interesting that the readMax function that I created on part 1 was also what I needed for part 2. https://github.com/massahud/advent-of-code-2023/blob/main/day02/day02.ipynb

crystal

(commented parts are for part 1)

input = File.read("input.txt").lines

limits = {"red"=> 12, "green"=> 13, "blue"=> 14}
# possibles = [] of Int32
powers = [] of Int32

input.each do |line|
	game = line.split(":")
	id = game[0].split()[1].to_i
	possible = true
	min = {"red"=> 0, "green"=> 0, "blue"=> 0}
	
	draws = game[1].split(";", &.split(",") do |cube|
		cubeinfo = cube.split
		num = cubeinfo[0].to_i
		
		min[cubeinfo[1]] = num if num > min[cubeinfo[1]] 
		
		# unless num <= limits[cubeinfo[1]]
		# 	possible = false
		# 	break
		# end 
	end )
	
	powers.push(min.values.product)
	# possibles.push(id) if possible
end
# puts possibles.sum
puts powers.sum

Python

Questions and feedback welcome!

import collections

from .solver import Solver

class Day02(Solver):
  def __init__(self):
    super().__init__(2)
    self.games = []

  def presolve(self, input: str):
    lines = input.rstrip().split('\n')
    for line in lines:
      draws = line.split(': ')[1].split('; ')
      draws = [draw.split(', ') for draw in draws]
      self.games.append(draws)

  def solve_first_star(self):
    game_id = 0
    total = 0
    for game in self.games:
      game_id += 1
      is_good = True
      for draw in game:
        for item in draw:
          count, colour = item.split(' ')
          if (colour == 'red' and int(count) > 12 or  # pylint: disable=too-many-boolean-expressions
                colour == 'blue' and int(count) > 14 or
                colour == 'green' and int(count) > 13):
            is_good = False
      if is_good:
        total += game_id
    return total

  def solve_second_star(self):
    total = 0
    for game in self.games:
      minimums = collections.defaultdict(lambda: 0)
      for draw in game:
        for item in draw:
          count, colour = item.split(' ')
          minimums[colour] = max(minimums[colour], int(count))
      power = minimums['red'] * minimums['blue'] * minimums['green']
      total += power
    return total

[LANGUAGE: C#]

Part 1:

var list = new List((await File.ReadAllLinesAsync(@".\Day 2\PuzzleInput.txt")));
int conter = 0;
foreach (var line in list)
{
    string[] split = line.Split(":");
    int game = Int32.Parse( split[0].Split(" ")[1]);
    string[] bagContents = split[1].Split(";");
    var max = new Dictionary() { { "red", 0 }, { "green", 0 }, { "blue", 0 } };
    foreach (var content in bagContents)
    {
        string pattern = @"(\d+) (\w+)";
        MatchCollection matches = Regex.Matches(content, pattern);

        foreach (Match match in matches)
        {
            int number = Int32.Parse(match.Groups[1].Value);
            string color = match.Groups[2].Value;
            max[color] = (max[color] >= number)? max[color] : number;
        }
    }
    conter += (max["red"] <= 12 && max["green"] <= 13 && max["blue"] <= 14) ? game : 0;

}
Console.WriteLine(conter);

Part 2:

var list = new List((await File.ReadAllLinesAsync(@".\Day 2\PuzzleInput.txt")));

int conter = 0;
foreach (var line in list)
{
    string[] split = line.Split(":");
    int game = Int32.Parse(split[0].Split(" ")[1]);
    string[] bagContents = split[1].Split(";");
        var max = new Dictionary();
    foreach (var content in bagContents)
    {
        string pattern = @"(\d+) (\w+)";

        MatchCollection matches = Regex.Matches(content, pattern);

        foreach (Match match in matches)
        {
            int number = Int32.Parse(match.Groups[1].Value);
            string color = match.Groups[2].Value;
            if (!max.ContainsKey(color))
                max[color] = number;
            else if(max[color] < number)
                max[color] = number;
        }
    }
    conter += max.Values.Aggregate(1, (total, value) => total *  value );

}
Console.WriteLine(conter);

My solution in python

input="""Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green"""

def parse(line):
    data={}
    data['game']=int(line[5:line.index(':')])
    data['hands']=[]
    for str in line[line.index(':')+1:].split(';'):
        h={'red':0,'green':0,'blue':0}
        for str2 in str.split(','):
            tmp=str2.strip(' ').split(' ')
            h[tmp[1]]=int(tmp[0])
        data['hands'].append(h)

    data['max_red']=max([x['red'] for x in data['hands']])
    data['max_green']=max([x['green'] for x in data['hands']])
    data['max_blue']=max([x['blue'] for x in data['hands']])
    data['power']=data['max_red']*data['max_green']*data['max_blue']
    data['possible'] = True
    if data['max_red'] > 12:
        data['possible'] = False
    if data['max_green'] > 13:
        data['possible'] = False
    if data['max_blue'] > 14:
        data['possible'] = False


    return data
def loadFile(path):
    with open(path,'r') as f:
        return f.read()

if __name__ == '__main__':
    input=loadFile('day2_input')
    res=[]
    total=0
    power_sum=0
    for row in input.split('\n'):
        data=parse(row)
        if data['possible']:
            total=total+data['game']
        power_sum=power_sum+data['power']
    print('total: %s, power: %s ' % (total,power_sum,))

Haskell

A rather opaque parser, but much shorter than I could manage with Parsec.

import Data.Bifunctor
import Data.List.Split
import Data.Map.Strict (Map)
import qualified Data.Map.Strict as Map
import Data.Tuple

readGame :: String -> (Int, [Map String Int])
readGame = bimap (read . drop 5) (map readPull . splitOn "; " . drop 2) . break (== ':')
  where
    readPull = Map.fromList . map (swap . bimap read tail . break (== ' ')) . splitOn ", "

possibleWith limit = and . Map.intersectionWith (>=) limit

main = do
  games <- map (fmap (Map.unionsWith max) . readGame) . lines <$> readFile "input02"
  let limit = Map.fromList [("red", 12), ("green", 13), ("blue", 14)]
  print $ sum $ map fst $ filter (possibleWith limit . snd) games
  print $ sum $ map (product . snd) games

Is anyone else like me, but it took me longer to understand what I was supposed to do on day 2 than on day 1? However, here is my solution written in Golang: https://github.com/alexruf/adventofcode2023/tree/main/d02

Just getting started with Rust, part 1 took a long time. Really amazed when I saw part 2, just needed to add 2 lines and was done due to the approach I had taken. Feedback more than welcome!

use std::{
    cmp, fs,
    io::{BufRead, BufReader},
};

fn main() {
    cube_conundrum_complete();
}

fn cube_conundrum_complete() {
    // Load the data file
    let filename = "./data/input_data/day_2_cubes.txt";
    let file = match fs::File::open(filename) {
        Ok(f) => f,
        Err(e) => {
            eprintln!("Error opening file: {}", e);
            return;
        }
    };
    let reader = BufReader::new(file);

    // iniatiate final results
    let mut total = 0;
    let mut total_power = 0;

    // loop over the games in the file
    for _line in reader.lines() {
        // Handle the data and extract game number and maximum number of cubes per color
        let (game_number, max_green, max_red, max_blue) = cube_conundrum_data_input(_line.unwrap());

        // Calculate the power for the day 2 result
        total_power += max_green * max_red * max_blue;

        //Calculate if the game was possible with the given number of cubes
        let result = cube_conundrum_game_possible(game_number, max_green, max_red, max_blue);
        total += result;
    }

    // print the final results
    println!("total part 1: {}", total);
    println!("total part 2: {}", total_power);
}

fn cube_conundrum_data_input(game_input: String) -> (i32, i32, i32, i32) {
    // Split the game number from the draws
    let (game_part, data_part) = game_input.split_once(":").unwrap();

    // Select the number of the round and parse into an integer
    let game_number: i32 = game_part
        .split_once(" ")
        .unwrap()
        .1
        .parse::()
        .expect("could not parse gamenumber to integer");

    // Split the data part into a vector both split on , and ; cause we only care about he maximum per color
    let parts: Vec<&str> = data_part
        .split(|c| c == ',' || c == ';')
        .map(|part| part.trim())
        .collect();

    // Set the intial values for the maximum per color to 0
    let (mut max_green, mut max_red, mut max_blue) = (0, 0, 0);

    // Loop over the different draws split them into color and nubmer of cubes, update maximum number of cubes
    for part in parts.iter() {
        let (nr_cubes_text, color) = part.split_once(" ").unwrap();
        let nr_cubes = nr_cubes_text
            .parse::()
            .expect("could not parse to integer");
        match color {
            "green" => max_green = cmp::max(max_green, nr_cubes),
            "red" => max_red = cmp::max(max_red, nr_cubes),
            "blue" => max_blue = cmp::max(max_blue, nr_cubes),
            _ => println!("unknown color: {}", color),
        };
    }

    return (game_number, max_green, max_red, max_blue);
}

fn cube_conundrum_game_possible(
    game_number: i32,
    max_green: i32,
    max_red: i32,
    max_blue: i32,
) -> i32 {
    // Compare the number of seen cubes per game with the proposed number. Return the game number if it was possible, otherwise 0
    let (comparison_red, comparison_green, comparison_blue) = (12, 13, 14);
    if max_green > comparison_green || max_red > comparison_red || max_blue > comparison_blue {
        return 0;
    };
    game_number
}

[Language: Lean4]

I'll only post the actual parsing and solution. I have written some helpers which are in other files, as is the main function. For the full code, please see my github repo.

structure Draw (α : Type) where
  red : α
  green : α
  blue : α
  deriving Repr

structure Game where
  id : Nat
  draw : List $ Draw Nat
  deriving Repr

def parse (input : String) : Option $ List Game :=
  let lines := input.splitTrim (. == '\n')
  let lines := lines.filter (not ∘ String.isEmpty)
  let parse_single_line : (String → Option Game):= λ (l : String) ↦ do
    let parse_id := λ (s : String) ↦ do
      let rest ← if s.startsWith "Game " then some (s.drop 5) else none
      rest.toNat?
    let parse_draw := λ (s : String) ↦ do
      let s := s.splitTrim (· == ',')
      let findAndRemoveTail := λ (s : String) (t : String) ↦
        if s.endsWith t then
          some $ String.dropRight s (t.length)
        else
          none
      let update_draw_parse := λ (pd : Option (Draw (Option String))) (c : String) ↦ do
        let old ← pd
        let red := findAndRemoveTail c " red"
        let green := findAndRemoveTail c " green"
        let blue := findAndRemoveTail c " blue"
        match red, green, blue with
        | some red, none, none => match old.red with
          | none => some $ {old with red := some red}
          | some _ => none
        | none, some green, none => match old.green with
          | none => some $ {old with green := some green}
          | some _ => none
        | none, none, some blue => match old.blue with
          | none => some $ {old with blue := some blue}
          | some _ => none
        | _, _, _  => none
      let parsed_draw ← s.foldl update_draw_parse (some $ Draw.mk none none none)
      let parsed_draw := {
        red := String.toNat? <$> parsed_draw.red,
        green := String.toNat? <$> parsed_draw.green,
        blue := String.toNat? <$> parsed_draw.blue : Draw _}
      let extractOrFail := λ (s : Option $ Option Nat) ↦ match s with
        | none => some 0
        | some none => none
        | some $ some x => some x
      let red ← extractOrFail parsed_draw.red
      let green ← extractOrFail parsed_draw.green
      let blue ← extractOrFail parsed_draw.blue
      pure { red := red, blue := blue, green := green : Draw _}
    let parse_draws := λ s ↦ List.mapM parse_draw $ s.splitTrim (· == ';')
    let (id, draw) ← match l.splitTrim (· == ':') with
    | [l, r] => Option.zip (parse_id l) (parse_draws r)
    | _ => none
    pure { id := id, draw := draw}
  lines.mapM parse_single_line

def part1 (games : List Game) : Nat :=
  let draw_possible := λ g ↦ g.red ≤ 12 && g.green ≤ 13 && g.blue ≤ 14
  let possible := flip List.all draw_possible
  let possible_games := games.filter (possible ∘ Game.draw)
  possible_games.map Game.id |> List.foldl Nat.add 0

def part2 (games : List Game) : Nat :=
  let powerOfGame := λ (g : Game) ↦
    let minReq := λ (c : Draw Nat → Nat) ↦
      g.draw.map c |> List.maximum? |> flip Option.getD 0
    minReq Draw.red * minReq Draw.green * minReq Draw.blue
  let powers := games.map powerOfGame
  powers.foldl Nat.add 0