comparison day6b.rb @ 7:6e0615e54e71

Restructure input parsing for day6b The rest of the algorithm is the same
author IBBoard <dev@ibboard.co.uk>
date Thu, 07 Dec 2023 08:23:04 +0000
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6:9d89489bc939 7:6e0615e54e71
1 #! /usr/bin/env ruby
2
3 if ARGV.length != 1
4 abort("Incorrect arguments - needs input file")
5 elsif not File.exist? (ARGV[0])
6 abort("File #{ARGV[0]} did not exist")
7 end
8
9 file = ARGV[0]
10
11 time, distance = File.open(file, "r").each_line(chomp: true).map {|v| v.split(":")[1].split(" ").join("").to_i}
12 events = [[time, distance]]
13
14 product = events.map do |event|
15 mid = (event[0].to_f / 2).floor
16 first_success = (1..mid).bsearch {|i| (event[0] - i) * i > event[1]}
17 num_success = (mid - first_success + 1) * 2
18 event[0].odd? ? num_success : num_success - 1
19 end.reduce(:*)
20
21 puts product