Rust

Part 1 Part 2

Fun with iterators! For the second part I went to regex for help.

Just getting my feet wet with coding after a decade of 0 programming. CS just didn’t work out for me in school, so I swapped over to math. Trying to use Python on my desktop, with Notepad++ and Windows Shell.

with open('01A_input.txt', 'r') as file:
    data = file.readlines()
    
print(data)
NumericList=[]

for row in data:
    word=row
    while not(word[0].isnumeric()):
        word=word[1:]
    while not(word[-1].isnumeric()):
        word=word[:-1]
    #print(word)
    tempWord=word[0]+word[-1]
    NumericList.append(int(tempWord))
    #print(NumericList)
Total=sum(NumericList)
print(Total)

with open('01A_input.txt', 'r') as file:
    data = file.readlines()
    
#print(data)
NumericList=[]
NumberWords=("one", "two", "three", "four", "five", "six", "seven", "eight", "nine")

def wordreplaceleft(wrd):
    if wrd.startswith("one"):
        return "1" + wrd[3:]
    elif wrd.startswith("two"):
        return "2" + wrd[3:]
    elif wrd.startswith("three"):
        return "3" + wrd[5:]
    elif wrd.startswith("four"):
        return "4" + wrd[4:]
    elif wrd.startswith("five"):
        return "5" + wrd[4:]
    elif wrd.startswith("six"):
        return "6" + wrd[3:]
    elif wrd.startswith("seven"):
        return "7" + wrd[5:]
    elif wrd.startswith("eight"):
        return "8" + wrd[5:]
    elif wrd.startswith("nine"):
        return "9" + wrd[4:]

def wordreplaceright(wrd):
    if wrd.endswith("one"):
        return wrd[:-3]+"1"
    elif wrd.endswith("two"):
        return wrd[:-3]+"2"
    elif wrd.endswith("three"):
        return wrd[:-5]+"3"
    elif wrd.endswith("four"):
        return wrd[:-4]+"4"
    elif wrd.endswith("five"):
        return wrd[:-4]+"5"
    elif wrd.endswith("six"):
        return wrd[:-3]+"6"
    elif wrd.endswith("seven"):
        return wrd[:-5]+"7"
    elif wrd.endswith("eight"):
        return wrd[:-5]+"8"
    elif wrd.endswith("nine"):
        return wrd[:-4]+"9"

for row in data:
    wordleft=row
    wordright=row
    
    if wordleft.startswith(NumberWords):
        wordleft=wordreplaceleft(wordleft)
    while not(wordleft[0].isnumeric()):
        if wordleft.startswith(NumberWords):
            wordleft=wordreplaceleft(wordleft)
        else:
            wordleft=wordleft[1:]
            
    if wordright.endswith(NumberWords):
        wordright=wordreplaceright(wordright)
    while not(wordright[-1].isnumeric()):
        if wordright.endswith(NumberWords):
            wordright=wordreplaceright(wordright)
        else:
            wordright=wordright[:-1]
    
    # while not(word[-1].isnumeric()):
        # word=word[:-1]
    # print(word)
    tempWord=wordleft[0]+wordright[-1]
    NumericList.append(int(tempWord))
    #print(NumericList)
Total=sum(NumericList)
print(Total)

Part 02 in Rust 🦀 :

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

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 number_map = HashMap::from([
        ("one", "1"),
        ("two", "2"),
        ("three", "3"),
        ("four", "4"),
        ("five", "5"),
        ("six", "6"),
        ("seven", "7"),
        ("eight", "8"),
        ("nine", "9"),
    ]);

    let mut total = 0;
    for _line in reader.lines() {
        let digits = get_text_numbers(_line.unwrap(), &number_map);
        if !digits.is_empty() {
            let digit_first = digits.first().unwrap();
            let digit_last = digits.last().unwrap();
            let mut cat = String::new();
            cat.push(*digit_first);
            cat.push(*digit_last);
            let cat: i32 = cat.parse().unwrap();
            total += cat;
        }
    }
    println!("{total}");
    Ok(())
}

fn get_text_numbers(text: String, number_map: &HashMap<&str, &str>) -> Vec {
    let mut digits: Vec = Vec::new();
    if text.is_empty() {
        return digits;
    }
    let mut sample = String::new();
    let chars: Vec = text.chars().collect();
    let mut ptr1: usize = 0;
    let mut ptr2: usize;
    while ptr1 < chars.len() {
        sample.clear();
        ptr2 = ptr1 + 1;
        if chars[ptr1].is_digit(10) {
            digits.push(chars[ptr1]);
            sample.clear();
            ptr1 += 1;
            continue;
        }
        sample.push(chars[ptr1]);
        while ptr2 < chars.len() {
            if chars[ptr2].is_digit(10) {
                sample.clear();
                break;
            }
            sample.push(chars[ptr2]);
            if number_map.contains_key(&sample.as_str()) {
                let str_digit: char = number_map.get(&sample.as_str()).unwrap().parse().unwrap();
                digits.push(str_digit);
                sample.clear();
                break;
            }
            ptr2 += 1;
        }
        ptr1 += 1;
    }

    digits
}

Have a snippet of Ruby, something I hacked together as part of a solution during the WFH morning meeting;

class String
  def to_numberstring(digits_only: false)
    tokens = { 
      one: 1, two: 2, three: 3,
      four: 4, five: 5, six: 6,
      seven: 7, eight: 8, nine: 9
    }.freeze
    ret = ""

    i = 0
    loop do
      if self[i] =~ /\d/
        ret += self[i]
      elsif !digits_only
        tok = tokens.find { |k, _| self[i, k.size] == k.to_s }
        ret += tok.last.to_s if tok
      end
      
      i += 1
      break if i >= size
    end

    ret
  end
end

Part-A in Python: https://github.com/pbui/advent-of-code-2023/blob/master/day01/day01-A.py

Was able to use a list comprehension to read the input.

Part-B in Python: https://github.com/pbui/advent-of-code-2023/blob/master/day01/day01-B.py

This was trickier…

Update: Modified Part 2 to be more functional again by using a map before I filter

Trickier than expected! I ran into an issue with Lua patterns, so I had to revert to a more verbose solution, which I then used in Hare as well.

Lua:

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

local sum = 0
for line in io.open("1.input"):lines() do
  local a, b = line:match("^.-(%d).*(%d).-$")
  if not a then
    a = line:match("%d+")
    b = a
  end
  if a and b then
    sum = sum + tonumber(a..b)
  end
end
print(sum)

local names = {
  ["one"] = 1,
  ["two"] = 2,
  ["three"] = 3,
  ["four"] = 4,
  ["five"] = 5,
  ["six"] = 6,
  ["seven"] = 7,
  ["eight"] = 8,
  ["nine"] = 9,
  ["1"] = 1,
  ["2"] = 2,
  ["3"] = 3,
  ["4"] = 4,
  ["5"] = 5,
  ["6"] = 6,
  ["7"] = 7,
  ["8"] = 8,
  ["9"] = 9,
}
sum = 0
for line in io.open("1.input"):lines() do
  local firstPos = math.huge
  local first
  for name, num in pairs(names) do
    local left = line:find(name)
    if left and left < firstPos then
      firstPos = left
      first = num
    end
  end
  local last
  for i = #line, 1, -1 do
    for name, num in pairs(names) do
      local right = line:find(name, i)
      if right then
        last = num
        goto found
      end
    end
  end
  ::found::
  sum = sum + tonumber(first * 10 + last)
end
print(sum)

Hare:

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

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

const numbers: [](str, int) = [
	("one", 1),
	("two", 2),
	("three", 3),
	("four", 4),
	("five", 5),
	("six", 6),
	("seven", 7),
	("eight", 8),
	("nine", 9),
	("1", 1),
	("2", 2),
	("3", 3),
	("4", 4),
	("5", 5),
	("6", 6),
	("7", 7),
	("8", 8),
	("9", 9),
];

fn solve(start: size) void = {
	const file = os::open("1.input")!;
	defer io::close(file)!;
	const scan = bufio::newscanner(file, types::SIZE_MAX);
	let sum = 0;
	for (let i = 1u; true; i += 1) {
		const line = match (bufio::scan_line(&scan)!) {
		case io::EOF =>
			break;
		case let line: const str =>
			yield line;
		};
		let first: (void | int) = void;
		let last: (void | int) = void;
		for (let i = 0z; i < len(line); i += 1) :found {
			for (let num = start; num < len(numbers); num += 1) {
				const start = strings::sub(line, i, strings::end);
				if (first is void && strings::hasprefix(start, numbers[num].0)) {
					first = numbers[num].1;
				};
				const end = strings::sub(line, len(line) - 1 - i, strings::end);
				if (last is void && strings::hasprefix(end, numbers[num].0)) {
					last = numbers[num].1;
				};
				if (first is int && last is int) {
					break :found;
				};
			};
		};
		sum += first as int * 10 + last as int;
	};
	fmt::printfln("{}", sum)!;
};

export fn main() void = {
	solve(9);
	solve(0);
};

deleted by creator

deleted by creator

[Rust] 11157/6740

use std::fs;

const m: [(&str, u32); 10] = [
    ("zero", 0),
    ("one", 1),
    ("two", 2),
    ("three", 3),
    ("four", 4),
    ("five", 5),
    ("six", 6),
    ("seven", 7),
    ("eight", 8),
    ("nine", 9)
];

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

    let mut u = 0;

    for l in s.lines() {
        let mut h = l.chars();
        let mut f = 0;
        let mut a = 0;

        for n in 0..l.len() {
            let u = h.next().unwrap();

            match u.is_numeric() {
                true => {
                    let v = u.to_digit(10).unwrap();
                    if f == 0 {
                        f = v;
                    }
                    a = v;
                },
                _ => {
                    for (t, v) in m {
                        if l[n..].starts_with(t) {
                            if f == 0 {
                                f = v;
                            }
                            a = v;
                        }
                    }
                },
            }
        }

        u += f * 10 + a;
    }

    println!("Sum: {}", u);
}

Link

APL

args ← {1↓⍵/⍨∨\⍵∊⊂'--'} ⎕ARG
inputs ← ⎕FIO[49]¨ args

words ← 'one' 'two' 'three' 'four' 'five' 'six' 'seven' 'eight' 'nine'
digits ← '123456789'

part1 ← {↑↑+/{(10×↑⍵)+¯1↑⍵}¨{⍵~0}¨+⊃(⍳9)+.×digits∘.⍷⍵}
"Part 1: ", part1¨ inputs

part2 ← {↑↑+/{(10×↑⍵)+¯1↑⍵}¨{⍵~0}¨+⊃(⍳9)+.×(words∘.⍷⍵)+digits∘.⍷⍵}
"Part 2: ", part2¨ inputs

)OFF

A new C solution: without lookahead or backtracking! I keep a running tally of how many letters of each digit word were matched so far: https://github.com/sjmulder/aoc/blob/master/2023/c/day01.c

int main(int argc, char **argv)
{
	static const char names[][8] = {"zero", "one", "two", "three",
	    "four", "five", "six", "seven", "eight", "nine"};
	int p1=0, p2=0, i,c;
	int p1_first = -1, p1_last = -1;
	int p2_first = -1, p2_last = -1;
	int nmatched[10] = {0};
	
	while ((c = getchar()) != EOF)
		if (c == '\n') {
			p1 += p1_first*10 + p1_last;
			p2 += p2_first*10 + p2_last;
			p1_first = p1_last = p2_first = p2_last = -1;
			memset(nmatched, 0, sizeof(nmatched));
		} else if (c >= '0' && c <= '9') {
			if (p1_first == -1) p1_first = c-'0';
			if (p2_first == -1) p2_first = c-'0';
			p1_last = p2_last = c-'0';
			memset(nmatched, 0, sizeof(nmatched));
		} else for (i=0; i<10; i++)
			/* advance or reset no. matched digit chars */
			if (c != names[i][nmatched[i]++])
				nmatched[i] = c == names[i][0];
			/* matched to end? */
			else if (!names[i][nmatched[i]]) {
				if (p2_first == -1) p2_first = i;
				p2_last = i;
				nmatched[i] = 0;
			}

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

Solution in C: https://github.com/sjmulder/aoc/blob/master/2023/c/day01-orig.c

Usually day 1 solutions are super short numeric things, this was a little more verbose. For part 2 I just loop over an array of digit names and use strncmp().

int main(int argc, char **argv)
{
	static const char * const nm[] = {"zero", "one", "two", "three",
	    "four", "five", "six", "seven", "eight", "nine"};
	char buf[64], *s;
	int p1=0,p2=0, p1f,p1l, p2f,p2l, d;
	
	while (fgets(buf, sizeof(buf), stdin)) {
		p1f = p1l = p2f = p2l = -1;

		for (s=buf; *s; s++)
			if (*s >= '0' && *s <= '9') {
				d = *s-'0';
				if (p1f == -1) p1f = d;
				if (p2f == -1) p2f = d;
				p1l = p2l = d;
			} else for (d=0; d<10; d++) {
				if (strncmp(s, nm[d], strlen(nm[d])))
					continue;
				if (p2f == -1) p2f = d;
				p2l = d;
				break;
			}

		p1 += p1f*10 + p1l;
		p2 += p2f*10 + p2l;
	}

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

Part 1 felt fairly pretty simple in Haskell:

import Data.Char (isDigit)

main = interact solve

solve :: String -> String
solve = show . sum . map (read . (\x -> [head x, last x]) . filter isDigit) . lines

Part 2 was more of a struggle, though I’m pretty happy with how it turned out. I ended up using concatMap inits . tails to generate all substrings, in order of appearance so one3m becomes ["","o","on","one","one3","one3m","","n","ne","ne3","ne3m","","e","e3","e3m","","3","3m","","m",""]. I then wrote a function stringToDigit :: String -> Maybe Char which simultaneously filtered out the digits and standardised them as Chars.

import Data.List (inits, tails)
import Data.Char (isDigit, digitToInt)
import Data.Maybe (mapMaybe)

main = interact solve

solve :: String -> String
solve = show . sum . map (read . (\x -> [head x, last x]) . mapMaybe stringToDigit . concatMap inits . tails) . lines
--                             |string of first&last digit| |find all the digits |   |all substrings of line|

stringToDigit "one"   = Just '1'
stringToDigit "two"   = Just '2'
stringToDigit "three" = Just '3'
stringToDigit "four"  = Just '4'
stringToDigit "five"  = Just '5'
stringToDigit "six"   = Just '6'
stringToDigit "seven" = Just '7'
stringToDigit "eight" = Just '8'
stringToDigit "nine"  = Just '9'
stringToDigit [x]
  | isDigit x         = Just x
  | otherwise         = Nothing
stringToDigit _       = Nothing

I went a bit excessively Haskell with it, but I had my fun!

I think I found a decently short solution for part 2 in python:

DIGITS = {
    'one': '1',
    'two': '2',
    'three': '3',
    'four': '4',
    'five': '5',
    'six': '6',
    'seven': '7',
    'eight': '8',
    'nine': '9',
}


def find_digit(word: str) -> str:
    for digit, value in DIGITS.items():
        if word.startswith(digit):
            return value
        if word.startswith(value):
            return value
    return ''


total = 0
for line in puzzle.split('\n'):
    digits = [
        digit for i in range(len(line))
        if (digit := find_digit(line[i:]))
    ]
    total += int(digits[0] + digits[-1])


print(total)

Python

Questions and feedback welcome!

import re

from .solver import Solver

class Day01(Solver):
  def __init__(self):
    super().__init__(1)
    self.lines = []

  def presolve(self, input: str):
    self.lines = input.rstrip().split('\n')

  def solve_first_star(self):
    numbers = []
    for line in self.lines:
      digits = [ch for ch in line if ch.isdigit()]
      numbers.append(int(digits[0] + digits[-1]))
    return sum(numbers)

  def solve_second_star(self):
    numbers = []
    digit_map = {
      "one": 1, "two": 2, "three": 3, "four": 4, "five": 5,
      "six": 6, "seven": 7, "eight": 8, "nine": 9, "zero": 0,
      }
    for i in range(10):
      digit_map[str(i)] = i
    for line in self.lines:
      digits = [digit_map[digit] for digit in re.findall(
          "(?=(one|two|three|four|five|six|seven|eight|nine|[0-9]))", line)]
      numbers.append(digits[0]*10 + digits[-1])
    return sum(numbers)