sharparam.com
Code for the Advent of Code event
aoc
advent-of-code
1# frozen_string_literal: true
2
3# Function courtesy of http://stackoverflow.com/a/3852809
4def invert(arr, values)
5 counts = values.each_with_object(Hash.new(0)) { |v, h| h[v] += 1 }
6 arr.reject { |e| counts[e] -= 1 unless counts[e].zero? }
7end
8
9def count_triangles(list)
10 list.reduce(0) do |a, e|
11 a + (e.permutation(2).all? { |perm| perm.inject(&:+) > invert(e, perm).first } ? 1 : 0)
12 end
13end