https://adventofcode.com/2020/day/1

advent_of_code_day_1.rb

require 'pathname'

values1 = Pathname.new('/users/james/advent_of_code_input_1.txt').readlines("\n").map{|l| l.chomp.to_i}.permutation(2).select{|a,b| a + b  == 2020}.map{|a, b| {product: a * b, values: [a, b]}}
puts "Part 1"
puts "Output = #{values1.first[:product]}"

values2 = Pathname.new('/users/james/advent_of_code_input_1.txt').readlines("\n").map{|l| l.chomp.to_i}.permutation(3).select{|a,b,c| a + b + c == 2020}.map{|a, b, c| {product: a * b * c, values: [a, b, c]}}

puts "Part 2"
puts "Output = #{values2.first[:product]}"