From b5425025a6b76b8e867569c5f902a385020de188 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Mon, 2 Dec 2024 10:24:02 +0000
Subject: [PATCH] 2024: d02: ex2: add solution

---
 2024/d02/ex2/ex2.py | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100755 2024/d02/ex2/ex2.py

diff --git a/2024/d02/ex2/ex2.py b/2024/d02/ex2/ex2.py
new file mode 100755
index 0000000..c1a4b7b
--- /dev/null
+++ b/2024/d02/ex2/ex2.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python
+
+import sys
+import itertools
+
+Report = list[int]
+
+
+def solve(input: list[str]) -> int:
+    def parse(input: list[str]) -> list[Report]:
+        return [[int(n) for n in line.split()] for line in input]
+
+    def is_safe(report: Report) -> bool:
+        def is_increasing_safe(report: Report):
+            for a, b in itertools.pairwise(report):
+                if a >= b:
+                    return False
+                if not 1 <= (b - a) <= 3:
+                    return False
+            return True
+
+        return is_increasing_safe(report) or is_increasing_safe(report[::-1])
+
+    # Dampening by brute force
+    def is_dampened_safe(report: Report) -> bool:
+        for i in range(len(report)):
+            dampened_report = report[:i] + report[i + 1 :]
+            if is_safe(dampened_report):
+                return True
+        return False
+
+    return sum(is_dampened_safe(report) for report in parse(input))
+
+
+def main() -> None:
+    input = sys.stdin.read().splitlines()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()