2024 day 8 part 1

2024/08/example

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+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............

2024/08/input

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+....h.....Q..............Y........................
+...............................Y........C.........
+...............m..........x................B......
+........................Y..............qB.........
+......g4.........................h..Y.....q...c...
+................n.....R...........................
+.......................................w........5.
+........g...m...........................w5........
+..n...........R.1................W.......q.5......
+.........h...n.................e..................
+...............................R..........B....C..
+.........4................................5.e.....
+.......0..4......n.......x..w.....................
+.......g.....m........x..b.....W.....B.......w....
+..............m........................3......C...
+........q...0.......h....................C.3......
+..................3.....................D.........
+...............R..........3.............X.........
+..............................W............k2.....
+..........7............................2..........
+...............A.............................X...2
+.......................c...x......................
+....................................d.............
+.....1......................d.....................
+...........1...........................e..........
+.........0.7K.........................2.........W.
+...b......0.....A.................................
+......................1....ic.....................
+......b......................i....................
+..Q.....b..........................A..E...........
+...7.........................V....................
+........A.....................v......d............
+........v............c...................8E.......
+..............................V........8.....E..N.
+......................6...........................
+.......I....M....................V................
+...G......................a.......8...............
+.........r.9........a...i..................X......
+...............r..i...............e............N..
+.....H...........k....9.....6...............8.....
+.v.....................6................V.........
+.........v.......a........k..........D............
+Ha..........k.........K........E.......d..........
+...............y.MG..............6....D...........
+.........H..G...M......9.K..............N.........
+.......G.........................K................
+...............M.........I.......D................
+..................................................
+....r....y................9.......................
+....y................................N............

2024/08/sample1

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+..........
+...#......
+#.........
+....a.....
+........a.
+.....a....
+..#.......
+......#...
+..........
+..........

2024/08/solution.nix

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+{lib, ...}: let
+
+  addVec = a: b: {x = a.x + b.x; y = a.y + b.y;};
+  subVec = a: b: {x = a.x - b.x; y = a.y - b.y;};
+
+  toCharList = builtins.foldl'
+    ({y, x, chars}: char:
+      if char == "." || char == "#" then {inherit y; x = x + 1; inherit chars;}
+      else if char == "\n" then {y = y + 1; x = 1; inherit chars;}
+      else {inherit y; x = x + 1; chars = chars ++ [{inherit x y char;}];}
+    )
+    {y = 1; x = 1; chars = [];} # yeah starting at 1,1 what you gonna do about it
+  ;
+
+  toNodes = {chars, ...}@amap: amap // {
+    nodes = map (antenna:
+      builtins.foldl' (acc: antenna2:
+        if antenna == antenna2 then acc
+        else if antenna.char != antenna2.char then acc
+        else let
+          delta = subVec antenna antenna2;
+        in acc ++ [(addVec antenna delta)]
+      ) [] chars
+    ) chars;
+  };
+
+  getUniqueNodes = amap: let
+    size = amap.x;
+  in amap.nodes
+      |> lib.concatLists
+      |> builtins.filter ({x, y}: x > 0 && y > 0 && x < size && y < size)
+      |> lib.unique
+  ;
+
+in {
+  inherit addVec subVec toCharList toNodes;
+
+  part1result = s: s
+    |> lib.trim
+    |> lib.stringToCharacters
+    |> toCharList
+    |> toNodes
+    |> getUniqueNodes
+    |> builtins.length
+  ;
+
+
+}

2024/08/solution.test.nix

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+{describe, it, ...}:
+let
+  pkgs = import <nixpkgs> {};
+  solution = import ./solution.nix pkgs;
+  exampleInput = pkgs.lib.readFile ./example;
+  sample1Input = pkgs.lib.readFile ./sample1;
+in [
+  (describe "part 1" [
+    (it "get's the answer with example input" {
+      actual = solution.part1result exampleInput;
+      expected = 14;
+    })
+    (it "get's the answer with other sample" {
+      actual = solution.part1result sample1Input;
+      expected = 4;
+    })
+    (it "adds vectors" {
+      actual = solution.addVec {x = 1; y = 2;} {x = 3; y = 4;};
+      expected = {x = 4; y = 6;};
+    })
+    (it "subtracts vectors" {
+      actual = solution.subVec {x = 4; y = 3;} {x = 1; y = 2;};
+      expected = {x = 3; y = 1;};
+    })
+  ])
+]