From 263693e45cc6665e3c149cdcd4ba05875b8f9004 Mon Sep 17 00:00:00 2001 From: Simon Green Date: Fri, 14 Jan 2022 15:21:19 +1100 Subject: sgreen solutions to challenge 147 --- challenge-147/sgreen/python/ch-2.py | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100755 challenge-147/sgreen/python/ch-2.py (limited to 'challenge-147/sgreen/python/ch-2.py') diff --git a/challenge-147/sgreen/python/ch-2.py b/challenge-147/sgreen/python/ch-2.py new file mode 100755 index 0000000000..c6424b9617 --- /dev/null +++ b/challenge-147/sgreen/python/ch-2.py @@ -0,0 +1,32 @@ +#!/usr/bin/env python + +import math + + +def pentagon_number(n): + return int(n * (3 * n - 1) / 2) + + +def is_pentagon_number(x): + n = math.sqrt(24 * x + 1) + 1 + return int(n / 6) if n % 6 == 0 else None + + +def main(): + n1 = 2 + while True: + p1 = pentagon_number(n1) + for n2 in range(1, n1): + p2 = pentagon_number(n2) + + s1 = is_pentagon_number(p1 + p2) + s2 = is_pentagon_number(p1 - p2) + + if s1 is not None and s2 is not None: + print(f'P({n1}) + P({n2}) = {p1} + {p2} = { p1 + p2 } = P({s1})') + print(f'P({n1}) - P({n2}) = {p1} - {p2} = { p1 - p2 } = P({s2})') + return + n1 += 1 + + +main() -- cgit