From c384d042233a8efd40ae1f08c4aef1de27e010e8 Mon Sep 17 00:00:00 2001
From: Christoph Stahl <christoph.stahl@uni-dortmund.de>
Date: Fri, 15 Dec 2023 10:13:44 +0100
Subject: [PATCH] Day 15

---
 aoc/day15.py | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 aoc/day15.py

diff --git a/aoc/day15.py b/aoc/day15.py
new file mode 100644
index 0000000..8ebb440
--- /dev/null
+++ b/aoc/day15.py
@@ -0,0 +1,70 @@
+from __future__ import annotations
+from typing import Optional, TypeAlias
+from dataclasses import dataclass, field
+
+from .aoc import Aoc2
+
+P1: TypeAlias = list[str]
+P2: TypeAlias = list[tuple[str, Optional[int]]]
+
+
+class Day15(Aoc2[P1, P2]):
+    def parseinput1(self, inpt: str) -> P1:
+        inpt = "".join(inpt.splitlines())
+        return inpt.split(",")
+
+    def parseinput2(self, inpt: str) -> P2:
+        inpt = "".join(inpt.splitlines())
+
+        output = []
+        for word in inpt.split(","):
+            if "-" in word:
+                output.append((word[:-1], None))
+            else:
+                name, boxnr = word.split("=")
+                output.append((name, int(boxnr)))
+        return output
+
+    @staticmethod
+    def hash(string: str) -> int:
+        waccum = 0
+        for char in string:
+            waccum += ord(char)
+            waccum *= 17
+            waccum = waccum % 256
+        return waccum
+
+    def part1(self, inpt: P1) -> int:
+        accum = 0
+        for word in inpt:
+            accum += self.hash(word)
+        return accum
+
+    def part2(self, inpt: P2) -> int:
+        boxes = {}
+        for name, op in inpt:
+            boxnr = self.hash(name)
+            if boxnr not in boxes:
+                boxes[boxnr] = {}
+            if op is None:
+                if name in boxes[boxnr]:
+                    del boxes[boxnr][name]
+            else:
+                boxes[boxnr][name] = op
+
+        accum = 0
+        for nr, box in boxes.items():
+            for pos, (label, lens) in enumerate(box.items()):
+                fp = (1 + nr) * (1 + pos) * lens
+                accum += fp
+
+        return accum
+
+
+def main() -> None:
+    aoc = Day15(2023, 15, example_code_nr2=0)
+    aoc.run()
+
+
+if __name__ == "__main__":
+    main()