Solution for day 15 (#12)

src/2023/15/2024_15.py

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+import dataclasses
+import re
+from typing import List
+
+from src.utils.data import load_data
+from src.utils.submission import submit_or_print
+
+
+@dataclasses.dataclass
+class Lens:
+    label: str
+    focal: int
+
+
+@dataclasses.dataclass
+class Box:
+    nr: int
+    lenses: List
+
+    def remove(self, label: str) -> None:
+        for lens in self.lenses:
+            if lens.label == label:
+                self.lenses.remove(lens)
+                break
+
+    def add(self, lens: Lens) -> None:
+        for i, l in enumerate(self.lenses):
+            if l.label == lens.label:
+                self.lenses.remove(l)
+                self.lenses.insert(i, lens)
+                break
+        else:
+            self.lenses.append(lens)
+
+    def power(self) -> int:
+        total = 0
+        for slot_nr, lens in enumerate(self.lenses, start=1):
+            total += (self.nr + 1) * slot_nr * lens.focal
+        return total
+
+
+def main(debug: bool) -> None:
+    input_data = load_data(debug)
+
+    steps = input_data.strip().split(",")
+
+    # part 1
+    total = 0
+    for step in steps:
+        total += hash(step)
+    result_part1 = total
+
+    # part 2
+    boxes = {i: Box(i, []) for i in range(256)}
+    for step in steps:
+        match = re.match("([a-z]+)(.)(.*)", step)
+        label_str = match.group(1)
+        op_str = match.group(2)
+        focal_str = match.group(3)
+
+        box_nr = hash(label_str)
+        box = boxes[box_nr]
+
+        if op_str == "-":
+            box.remove(label_str)
+        elif op_str == "=":
+            box.add(Lens(label_str, int(focal_str)))
+
+    total = 0
+    for box in boxes.values():
+        total += box.power()
+    result_part2 = total
+
+    submit_or_print(result_part1, result_part2, debug)
+
+
+def hash(string: str) -> int:
+    cur = 0
+    for ch in string:
+        cur += ord(ch)
+        cur *= 17
+        cur %= 256
+    return cur
+
+
+if __name__ == "__main__":
+    debug_mode = True
+    # debug_mode = False
+    main(debug_mode)

src/2023/15/sample_input.txt

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+abc=1,xxx=2,yyy=3,abc=9,abc-