Stub out day 18 in Java

Author: fwcd

README.md

@@ -23,6 +23,7 @@ My solutions to the [Advent of Code 2024](https://adventofcode.com/2024), writte
 - [x] [**Day 15**](day15): [C++](day15/src/day15.cpp)
 - [x] [**Day 16**](day16): [Kotlin](day16/src/day16.kts)
 - [x] [**Day 17**](day17): [C#](day17/src/day17.cs) (using Z3 to solve part 2)
+- [ ] [**Day 18**](day18): [Java](day18/src/Day18.java)
 
 ## Development
 

day18/derivation.nix

@@ -0,0 +1,25 @@
+{ stdenv, jdk21 }:
+  stdenv.mkDerivation {
+    name = "advent-of-code-2024-day18";
+    src = ./src;
+
+    buildInputs = [
+      jdk21
+    ];
+
+    buildPhase = ''
+      javac Day18.java
+    '';
+
+    installPhase = ''
+      mkdir -p $out/{bin,share}
+      cp *.class $out/share
+
+      cat <<EOF > $out/bin/day18
+      #!/bin/sh
+      "${jdk21.outPath}/bin/java" -classpath "\$(dirname "\$0")/../share" Day18 "\$@"
+      EOF
+
+      chmod +x $out/bin/day18
+    '';
+  }

day18/flake.lock

@@ -0,0 +1,28 @@
+{
+  description = "Advent of Code 2024 - Day 18 solution";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+    in {
+      packages = forAllSystems (system:
+        let
+          pkgs = import nixpkgs { inherit system; };
+        in {
+          default = pkgs.callPackage ./derivation.nix {};
+        }
+      );
+
+      apps = forAllSystems (system: {
+        default = {
+          type = "app";
+          program = "${self.packages.${system}.default}/bin/day18";
+        };
+      });
+    };
+}

day18/flake.nix

@@ -0,0 +1,25 @@
+5,4
+4,2
+4,5
+3,0
+2,1
+6,3
+2,4
+1,5
+0,6
+3,3
+2,6
+5,1
+1,2
+5,5
+2,5
+6,5
+1,4
+0,4
+6,4
+1,1
+6,1
+1,0
+0,5
+1,6
+2,0