Mercurial > repos > other > adventofcode2023
comparison day6.rb @ 6:9d89489bc939
Day 6 part 1 - calculate times above range
| author | IBBoard <dev@ibboard.co.uk> |
|---|---|
| date | Thu, 07 Dec 2023 08:16:30 +0000 |
| parents | |
| children | 51e5f26dc81e |
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| 5:a14f6eca67db | 6:9d89489bc939 |
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| 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 times, distances = File.open(file, "r").each_line(chomp: true).map {|v| v.split(":")[1].split(" ").map(&:to_i)} | |
| 12 events = times.zip(distances) | |
| 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 |