Update Day 07

2024/day05/day05a.py

@@ -0,0 +1,20 @@
+from collections import defaultdict
+
+input = [line.strip() for line in open('/home/bandeira/git.bandeira/aoc/2024/day05/input.day05') if line.strip()]
+
+rules = defaultdict(set)
+for line in input:
+    if '|' in line:
+        a, b = map(int, line.split('|'))
+        rules[a].add(b)
+
+updates = [list(map(int, line.split(','))) for line in input if ',' in line]
+
+is_correct = lambda u: all(not (set(u[:i]) & rules[u[i]]) for i in range(len(u)))
+
+ans1 = sum(u[len(u) // 2] for u in updates if is_correct(u))
+
+ans2 = sum(next(n for n in update if len(rules[n] & set(update)) == len(update) // 2)
+                for update in updates if not is_correct(update))
+
+print(f"{ans1}\n{ans2}")