Day 10

day10/part2.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+from functools import reduce
+
+lines = (x.strip() for x in open("input.txt"))
+
+cnt = []
+OPEN, CLOSE, PENALTY = "([{<", ")]}>", [1, 2, 3, 4]
+MAP_CLOSE, MAP_PENALTY = dict(zip(OPEN, CLOSE)), dict(zip(OPEN, PENALTY))
+for line in lines:
+    success = True
+    stack = []
+    for char in line:
+        if char in OPEN:
+            stack.append(char)
+        elif MAP_CLOSE[stack.pop()] != char:
+            success = False
+            break
+    if success:
+        cnt.append(reduce(lambda p, c: p*5 + MAP_PENALTY[c], stack[::-1], 0))
+
+cnt.sort()
+print(cnt[len(cnt) // 2])