2 files changed, 30 insertions(+), 0 deletions(-)

M .gitignore
A day03/day03b.py

@@ 1,2 1,3 @@
 *.o
 *.in
+__pycache__/

@@ 0,0 1,29 @@
+#! /usr/bin/env python3
+# vim:fenc=utf-8
+#
+# Copyright © 2022 Adrian Perez de Castro <aperez@igalia.com>
+#
+# Distributed under terms of the MIT license.
+
+from common import item_priority
+import sys
+
+def common_group_item(a, b, c):
+    common = frozenset(a) & frozenset(b) & frozenset(c)
+    assert len(common) == 1
+    for item in common:
+        return item
+
+def line_groups(lines):
+    lines = iter(lines)
+    while True:
+        try:
+            yield (next(lines).strip(),
+                   next(lines).strip(),
+                   next(lines).strip())
+        except StopIteration:
+            return
+
+print(sum((item_priority(item)
+           for item in (common_group_item(a, b, c)
+                        for a, b, c in line_groups(sys.stdin.readlines())))))