19.1

1 files changed, 31 insertions, 0 deletions

diff --git a/20/py/d19.py b/20/py/d19.py
new file mode 100644
index 0000000..7317c44
--- /dev/null
+++ b/20/py/d19.py
@@ -0,0 +1,31 @@
+import aoc20
+import sys
+from collections import defaultdict
+import functools
+import re
+
+
+def pt1(_in):
+    rules = dict()
+    for rule in "".join(_in).split("\n\n")[0].split("\n"):
+        rule = rule.replace("\"", "").split(": ")
+        rules[rule[0]] = rule[1] if rule[1] in "ab" else "( {} )".format(rule[1])
+
+    @functools.cache
+    def format_rule(rule):
+        if rule not in rules:
+            return rule
+        return " ".join(format_rule(token) for token in rules[rule].split())
+
+    regex = re.compile(format_rule("0").replace(" ", ""))
+    return sum(1 for line in "".join(_in).split("\n\n")[1][:-1].split("\n") if regex.fullmatch(line))
+
+
+def pt2(_in):
+    pass
+
+
+if __name__ == "__main__":
+    _in = aoc20.read_input(sys.argv[1:], 19)
+    print(pt1(_in))
+    print(pt2(_in))