This topic is about Day 5 of the Advent of Code 2021 . We have a private leaderboard (shared with users of Erlang Forums ): https://adventofcode.com/2021/leaderboard/private/view/370884 The entry code is: 370884-a6a71927

Here is my solution: https://github.com/bjorng/advent-of-code-2021/blob/6ca39045ed4cef5c81d45a76f1590d0098e6b5c4/day05/lib/day05.ex

This one was nicer to me. I like my approach for handling the lines, but I don’t like my approach to parsing the input. There has to be a pattern matching on binaries but it’s beyond me. https://github.com/stevensonmt/advent_of_code/blob/ace53043d4d95ffdb60f0d47c396f87a6f5562a2/2021/day5/lib/day5.e…

def part_1 do @path |> parse_input() |> Enum.filter(fn line -> line_direction(line) in @orthogonal end) |> plot_lines_to_map() |> Enum.count(fn {_k, v} -> v > 1 end) end Part 2 simply removes the Enum.filter Full solution here

My solution Today was significatively simpler than yesterday, but I had to remember my vector algebra :slight_smile: To calculate the intermediate points, I used: def fill_points({x1,y1,x2,y2}) do {dx, dy} = {x2 - x1, y2 - y1} slope = {step(dx), step(dy)} do_fill({x1, y1}, {x2, y2},…

maybe you will like my way of parsing the input? File.read!("day_5.txt") |> String.split(["\n", ",", " -> "], trim: true) |> Enum.map(&String.to_integer/1) |> Enum.chunk_every(4) |> Enum.map(&List.to_tuple/1) We can split the file in all the special content we have, a…

This one was fun. Beautiful use of pipe and pattern: defmodule AdventOfCode.Y2021.Day05 do use AdventOfCode.Helpers.InputReader, year: 2021, day: 5 def run_1, do: input!() |> parse() |> overlaps(false) def run_2, do: input!() |> parse() |> overlaps(true) def parse(data), do: Enum.map(Strin…

Feels regex is justified here, maybe? defmodule Aoc2021.Vents do def overlaps(coords) do regex = ~r/(\d+),(\d+) -> (\d+),(\d+)/ coords |> String.split("\n", trim: true) |> Enum.map(fn line -> Regex.run(regex, line, capture: :all_but_first) |> Enum.map(&String.to_integ…

Here is my solution for part 1. For part two, removing the filter does the job. expend_lines = fn [{x, y1}, {x, y2}] -> y = y1..y2 Enum.zip(List.duplicate(x, Enum.count(y)), y1..y2) [{x1, y}, {x2, y}] -> x = x1..x2 Enum.zip(x1..x2, List.duplicate(y, Enum.count(x))) [{x1, y1}…

[image] Malian: “1.1…11.\n.111…2…\n…2.1.111.\n…1.2.2…\n.112313211\n…1.2…\n…1…1…\n.1…1…\n1…1.\n222111…” IO.puts would work, I think: iex(5)> input = "1.1...11.\n.111...2...\n...2.1.111.\n...1.2.2...\n.112313211\n...1.2...\n...1...1...\n.1...1...\n1...1.\n222111..." iex(6)> IO.puts input 1.1..…

Elixir Programming Language Forum

Advent of Code 2021 - Day 5

Learning Resources Coding Challenges

princemaple December 5, 2021, 5:42am 3

https://github.com/princemaple/aoc/blob/main/2021/day5.exs