From fb0f39b76651baf2ed91a68a2565ac5c27f989ff Mon Sep 17 00:00:00 2001
From: Thibaud <thibaud.gasser@gmx.com>
Date: Mon, 28 Jul 2025 10:59:28 +0200
Subject: [PATCH] 2018 day 2

---
 2018/day2/day2.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 2018/day2/day2.py

diff --git a/2018/day2/day2.py b/2018/day2/day2.py
new file mode 100644
index 0000000..f9c06f1
--- /dev/null
+++ b/2018/day2/day2.py
@@ -0,0 +1,30 @@
+from collections import Counter
+
+
+def part2(ids):
+    for id_a in ids:
+        for id_b in ids:
+            common_letters = [a for a, b in zip(id_a, id_b) if a == b]
+            if len(common_letters) == len(id_a) - 1:
+                res = "".join(common_letters)
+                print("Part 2: ", res)
+                return
+
+
+def main(lines):
+    total_twice, total_thrice = 0, 0
+    for line in lines:
+        c = Counter(line)
+        total_twice += 1 if [k for k,v in c.items() if v == 2] != [] else 0
+        total_thrice += 1 if [k for k,v in c.items() if v == 3] != [] else 0
+    print(f"Part 1: ", total_twice * total_thrice)
+
+    part2(lines)
+
+
+if __name__ == "__main__":
+    import sys
+    infile = sys.argv[1] if len(sys.argv) > 1 else "example.txt"
+    with open(infile) as inp:
+        main([l.rstrip() for l in inp.readlines()])
+