From 144a8af49b77cc760a809c35d6494f87641dfa46 Mon Sep 17 00:00:00 2001 From: Steven Wilson Date: Tue, 15 Jun 2021 15:21:58 +0100 Subject: add math method --- challenge-117/steven-wilson/python/ch-1.py | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/challenge-117/steven-wilson/python/ch-1.py b/challenge-117/steven-wilson/python/ch-1.py index a3870ba254..9978605acd 100755 --- a/challenge-117/steven-wilson/python/ch-1.py +++ b/challenge-117/steven-wilson/python/ch-1.py @@ -7,11 +7,18 @@ if __name__ == "__main__": file = open(filename) lines = file.readlines() line_numbers = [int(line.split(',')[0]) for line in lines] - line_numbers.sort() - number = 1 - for line_number in line_numbers: - if number != line_number: - break - else: - number += 1 + # Math method + sum_of_line_numbers = sum(line_numbers) + sum_of_range = sum(range(1, (len(line_numbers) + 2))) + number = sum_of_range - sum_of_line_numbers + + # Iterative method +# line_numbers.sort() +# number = 1 +# for line_number in line_numbers: +# if number != line_number: +# break +# else: +# number += 1 + print("The missing row number is %d" % number) \ No newline at end of file -- cgit