Stub out day 6 in Zig

Author: fwcd

README.md

@@ -11,6 +11,7 @@ My solutions to the [Advent of Code 2024](https://adventofcode.com/2024), writte
 - [x] [**Day 03**](day03): [Perl](day03/src/day03.pl)
 - [x] [**Day 04**](day04): [C](day04/src/day04.c)
 - [x] [**Day 05**](day05): [Prolog](day05/src/day05.pl)
+- [ ] [**Day 06**](day06): [Zig](day06/src/day06.zig)
 
 ## Development
 

day06/derivation.nix

@@ -0,0 +1,21 @@
+{ stdenv, zig }:
+  stdenv.mkDerivation {
+    name = "advent-of-code-2024-day06";
+    src = ./src;
+    sourceRoot = ".";
+
+    nativeBuildInputs = [
+      zig
+    ];
+
+    buildPhase = ''
+      mkdir out cache
+
+      zig build-exe --global-cache-dir cache -femit-bin=out/day06 -O ReleaseSafe src/day06.zig
+    '';
+
+    installPhase = ''
+      mkdir -p $out/bin
+      cp out/day06 $out/bin
+    '';
+  }

day06/flake.lock

@@ -0,0 +1,28 @@
+{
+  description = "Advent of Code 2024 - Day 06 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/day06";
+        };
+      });
+    };
+}

day06/flake.nix

@@ -0,0 +1,10 @@
+....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...

day06/resources/demo.txt

@@ -0,0 +1,77 @@
+const std = @import("std");
+
+const allocator = std.heap.page_allocator;
+
+const List = std.ArrayList;
+const Map = std.AutoHashMap;
+const String = []u8;
+const Matrix = List(String);
+const Vec2 = struct { x: i32, y: i32 };
+const State = struct { pos: Vec2, dir: Vec2 };
+
+fn Set(comptime T: type) type {
+    return Map(T, void);
+}
+
+fn width(matrix: Matrix) i32 {
+    return matrix.items[0].len;
+}
+
+fn height(matrix: Matrix) i32 {
+    return matrix.items.len;
+}
+
+fn parseDirection(c: u8) ?Vec2 {
+    return switch (c) {
+        '^' => .{ .x = 0, .y = -1 },
+        'v' => .{ .x = 0, .y = 1 },
+        '<' => .{ .x = -1, .y = 0 },
+        '>' => .{ .x = 1, .y = 0 },
+        else => null,
+    };
+}
+
+fn findStart(matrix: Matrix) State {
+    for (0..height(matrix)) |i| {
+        for (0..width(matrix)) |j| {
+            const dir = parseDirection(matrix[i][j]);
+            if (dir != null) {
+                return dir;
+            }
+        }
+    }
+    std.debug.panic("Could not find start");
+}
+
+pub fn main() !u8 {
+    const args = try std.process.argsAlloc(allocator);
+    if (args.len <= 1) {
+        try std.io.getStdErr().writer().print("Usage: {s} <path to input>\n", .{args[0]});
+        return 1;
+    }
+
+    var matrix = Matrix.init(allocator);
+    defer {
+        for (matrix.items) |line| {
+            allocator.free(line);
+        }
+        matrix.deinit();
+    }
+
+    var buffer: [1024]u8 = undefined;
+    var file = try std.fs.cwd().openFile(args[1], .{});
+    var bufReader = std.io.bufferedReader(file.reader());
+    var reader = bufReader.reader();
+    defer file.close();
+
+    while (try reader.readUntilDelimiterOrEof(&buffer, '\n')) |bufLine| {
+        const line = try allocator.dupeZ(u8, bufLine);
+        try matrix.append(line);
+    }
+
+    for (matrix.items) |line| {
+        std.log.debug("{s}", .{line});
+    }
+
+    return 0;
+}

day06/resources/input.txt

@@ -38,5 +38,12 @@
     },
     "path": "day05/src/day05.pl",
     "completed": true
+  },
+  {
+    "lang": {
+      "codemirror": "zig",
+      "name": "Zig"
+    },
+    "path": "day06/src/day06.zig"
   }
 ]