Answer for ADDREV challenge in SPOJ

gistfile1.rb

cases = gets.chomp.to_i

def valid_numeric_input?(input)
  input.zero?
end

def reverse_num(num)
  num.to_s.reverse.to_i
end

def rev_add(data)
  sum = 0
  data.each do |rec|
    sum += reverse_num(rec)
  end
  reverse_num(sum)
end

valid_numeric_input?(cases)
results = []

cases.times do |index|
  input_str = gets.chomp
  nums = input_str.split(' ').map(&:to_i)
  results[index] = rev_add(nums)
end

results.each { |e| puts e }

You can remove method 'rev_add' and do the changes as follows:
cases.times do |index|
nums = gets.chomp.split(' ').map { |n| reverse_num(n) }
results[index] = reverse_num(nums.to_a.reduce(&:+))
end