AtCoder ABC #012 [Ruby]

abc012-a.rb

a, b = gets.chomp.split(" ").map(&:to_i)
puts "#{b} #{a}"

abc012-b.rb

n = gets.chomp.to_i
h = n / 3600
n -= h * 3600
m = n / 60
n -= m * 60
printf("%02i:%02i:%02i\n", h, m, n)

abc012-c.rb

n = gets.chomp.to_i
kuku = Hash.new{|h, k| h[k] = Array.new()}
sum = 0
(1..9).each do |i|
  (1..9).each do |j|
    sum += i * j
    kuku[i*j] << "#{i} x #{j}"
  end
end
puts kuku[sum - n]