1 files changed, 33 insertions, 0 deletions
diff --git a/aoc/2025/02/python.py b/aoc/2025/02/python.py
new file mode 100755
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+++ b/aoc/2025/02/python.py
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+#!/usr/bin/env python3
+
+
+from itertools import accumulate
+from bisect import bisect_left, bisect_right
+from functools import cache
+
+rs = [(int(a), int(b)) for r in input().split(",") for [a, b] in [r.split("-")]]
+N = max(len(str(x)) for r in rs for x in r)
+
+
+@cache
+def memo(p2: bool):
+    ids = sorted(
+        {
+            int(str(n) * reps)
+            for n in range(10 ** (N // 2))
+            for reps in range(2, N // len(str(n)) + 1 if p2 else 3)
+        }
+    )
+    sums = list(accumulate(ids))
+    return ids[1:], sums
+
+
+def prefix_sum(a: int, b: int, ids: list[int], sums: list[int]):
+    return sums[bisect_right(ids, b)] - sums[bisect_left(ids, a)]
+
+
+silver = sum(prefix_sum(*r, *memo(False)) for r in rs)
+gold = sum(prefix_sum(*r, *memo(True)) for r in rs)
+
+print("silver:", silver)
+print("gold:", gold)