2024 day 18 part 1

2024/18/example.txt

@@ -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

2024/18/solution.nix

@@ -0,0 +1,52 @@
+{lib, input ? "", my-lib, ...}@pkgs: rec {
+  inherit pkgs;
+  inherit lib;
+  inherit (builtins) elemAt genList elem concatStringsSep;
+  inherit (lib) splitString;
+  inherit (lib.strings) toIntBase10;
+
+  init = input: input |> lib.trim
+    |> splitString "\n"
+    |> map (line: let c = splitString "," line; in {
+      x = elemAt c 0 |> toIntBase10;
+      y = elemAt c 1 |> toIntBase10;
+    })
+  ;
+
+  genChart = size: coords: genList (y: genList (x:
+    if x == 0 && y == 0 then "S" else
+    if x == size - 1 && y == size - 1 then "E" else
+    if elem {inherit x y;} coords then "#" else "."
+  ) size) size;
+
+  chartToStr = chart: chart |> (map (concatStringsSep "")) |> concatStringsSep "\n";
+
+  mkSolution = {size, bytes, input}: rec {
+    inherit size bytes input;
+    walls = lib.sublist 0 bytes (init input);
+    chart = genChart size walls;
+    part1result = dijkstra.toGoal.steps;
+    dijkstra = my-lib.dijkstra {
+      pos = {x = 0; y = 0;};
+      goal = {x = size - 1; y = size - 1;};
+      chart = chart;
+      width = size;
+      height = size;
+    };
+  };
+
+  example = mkSolution {
+    size = 7;
+    bytes = 12;
+    input = lib.readFile ./example.txt;
+  };
+
+  real = mkSolution {
+    size = 71;
+    bytes = 1024;
+    input = input;
+  };
+
+  # not 272, too high
+
+}