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tanelikaivola/aoc202019.py Secret

Created December 20, 2020 00:55
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  1. tanelikaivola created this gist Dec 20, 2020.
    16 changes: 16 additions & 0 deletions aoc202019.py
    View file
    Original file line number Diff line number Diff line change
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    import regex
    def defs(rules_s):
    for rule in rules_s.split('\n'):
    n,s = rule.split(': ',1)
    s = regex.sub(r'\s*(\d+)\s*',r'(?&r\1)',s)
    s = regex.sub(r'"(\w+)"',r'\1',s)
    yield "(?P<r{}>{})".format(n,s)
    rules_s, messages_s = open('./input').read().split("\n\n",1)
    r=regex.compile(r'(?(DEFINE){})^(?&r0)$'.format(''.join(defs(rules_s))))
    print("part1:", sum(1 if r.match(msg) else 0 for msg in messages_s.split('\n')))
    rules_s, messages_s = open('./input').read().split("\n\n",1)
    rules_s = regex.sub(r'8: 42','8: 42 | 42 8',rules_s)
    rules_s = regex.sub(r'11: 42 31','11: 42 31 | 42 11 31',rules_s)
    # .. or replace with what you had in the instructions page
    r=regex.compile(r'(?(DEFINE){})^(?&r0)$'.format(''.join(defs(rules_s))))
    print("part2:", sum(1 if r.match(msg) else 0 for msg in messages_s.split('\n')))