「🎉」 init(2025): day 1

2024/day08/.envrc

@@ -0,0 +1 @@
+use flake

2024/day08/flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1733384649,
+        "narHash": "sha256-K5DJ2LpPqht7K76bsxetI+YHhGGRyVteTPRQaIIKJpw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "190c31a89e5eec80dd6604d7f9e5af3802a58a13",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-24.05",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

2024/day08/flake.nix

@@ -0,0 +1,29 @@
+{
+  description = "a minimal test development environment for ruby";
+
+  inputs = {
+
+    nixpkgs = {
+      url = "nixpkgs/nixos-24.05";
+      flake = false;
+	};
+
+  };
+
+  outputs = inputs@{ nixpkgs, ... }:
+	{
+    devShell = {
+      x86_64-linux = let
+        pkgs = import nixpkgs { system = "x86_64-linux"; };
+	  in pkgs.mkShell {
+        packages = with pkgs; [
+          gcc ruby
+        ];
+        shellHook = ''
+          export CC=gcc
+          echo -e "\x1B[0;33mentering ruby minimalist test development environment...\x1B[0m"
+        '';
+      };
+    };
+  };
+}

2024/day08/part1.rb

@@ -0,0 +1,47 @@
+require 'set'
+
+if File.exists?("input.txt")
+  file = File.open("input.txt")
+  file_data = file.read
+  file.close
+else
+  file_data = "............\n........0...\n.....0......\n.......0....\n....0.......\n......A.....\n............\n............\n........A...\n.........A..\n............\n............"
+end
+
+antennas = []
+map = file_data.split("\n")
+map.each_with_index do |row, r|
+  row.chars.each_with_index do |char, c|
+    antennas << [c, r, char] if char != '.'
+  end
+end
+
+antinodes = Set.new
+
+antennas.each_with_index do |(x1, y1, value1), i|
+  antennas.each_with_index do |(x2, y2, value2), j|
+    next if i == j
+    next unless  value1 == value2
+
+    x_dir = x2 - x1
+    y_dir = y2 - y1
+
+    [1, -1].each do |dir|
+      if dir > 0
+        x_point = x1 - x_dir * dir
+      else
+        x_point = x2 - x_dir * dir
+      end
+      
+      if dir > 0
+        y_point = y1 - y_dir * dir
+      else
+        y_point = y2 - y_dir * dir
+      end
+
+      antinodes.add([x_point, y_point]) if (x_point.between?(0, map.size - 1) && y_point.between?(0, map[0].size - 1))
+    end
+  end
+end
+
+puts antinodes.size

2024/day08/part2.rb

@@ -0,0 +1,47 @@
+require 'set'
+
+if File.exists?("input.txt")
+  file = File.open("input.txt")
+  file_data = file.read
+  file.close
+else
+  file_data = "............\n........0...\n.....0......\n.......0....\n....0.......\n......A.....\n............\n............\n........A...\n.........A..\n............\n............"
+end
+
+antennas = []
+map = file_data.split("\n")
+map.each_with_index do |row, r|
+  row.chars.each_with_index do |char, c|
+    antennas << [c, r, char] if char != '.'
+  end
+end
+
+antinodes = Set.new
+
+antennas.each_with_index do |(x1, y1, value1), i|
+  antennas.each_with_index do |(x2, y2, value2), j|
+    next if i == j
+    next unless  value1 == value2
+
+    x_dir = x2 - x1
+    y_dir = y2 - y1
+
+    [1, -1].each do |dir|
+        x_point = x1
+        y_point = y1
+
+      loop do
+        x_point = x_point - x_dir * dir
+        y_point = y_point - y_dir * dir
+
+        if (!x_point.between?(0, map.size - 1) || !y_point.between?(0, map[0].size - 1))
+          break
+        end
+
+       antinodes.add([x_point, y_point])
+      end
+    end
+  end
+end
+
+puts antinodes.size