Day 15

day15.py

@@ -0,0 +1,71 @@
+from tools.aoc import AOCDay
+from typing import Any
+
+
+def HASH(s: str) -> int:
+    this_hash = 0
+    for c in s:
+        this_hash = (this_hash + ord(c)) * 17 % 256
+
+    return this_hash
+
+
+class Box:
+    def __init__(self, nr: int):
+        self.nr = nr
+        self.labels = []
+        self.focal_lengths = []
+
+    def add(self, label: str, focal_length: int) -> None:
+        if label in self.labels:
+            self.focal_lengths[self.labels.index(label)] = focal_length
+        else:
+            self.labels.append(label)
+            self.focal_lengths.append(focal_length)
+
+    def remove(self, label: str) -> None:
+        if label not in self.labels:
+            return
+
+        p = self.labels.index(label)
+        self.labels.pop(p)
+        self.focal_lengths.pop(p)
+
+    def get_focus_power(self) -> int:
+        return sum((self.nr + 1) * (x + 1) * l for x, l in enumerate(self.focal_lengths))
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (1320, "input15_test"),
+            (513158, "input15"),
+        ],
+        [
+            (145, "input15_test"),
+            (200277, "input15"),
+        ]
+    ]
+
+    def part1(self) -> Any:
+        return sum(HASH(c) for c in self.getInput().split(","))
+
+    def part2(self) -> Any:
+        boxes = {}
+        for s in self.getInput().split(","):
+            if '-' in s:
+                label = s[:-1]
+                label_hash = HASH(label)
+                boxes.setdefault(label_hash, Box(label_hash)).remove(label)
+            else:
+                label, f_str = s.split("=")
+                focal_length = int(f_str)
+                label_hash = HASH(label)
+                boxes.setdefault(label_hash, Box(label_hash)).add(label, focal_length)
+
+        return sum(x.get_focus_power() for x in boxes.values())
+
+
+if __name__ == '__main__':
+    day = Day(2023, 15)
+    day.run(verbose=True)

inputs/input15_test

@@ -0,0 +1 @@
+rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7