diff --git a/archive/r/ruby/merge-sort.rb b/archive/r/ruby/merge-sort.rb new file mode 100644 index 000000000..72e1585f1 --- /dev/null +++ b/archive/r/ruby/merge-sort.rb @@ -0,0 +1,50 @@ +# frozen_string_literal: true + +def usage! + abort %(Usage: please provide a list of at least two integers to sort in the format "1, 2, 3, 4, 5") +end + +def parse_input + raw = ARGV.first + usage! if raw.nil? || raw.strip.empty? + + numbers = raw.split(",").map { Integer(it.strip) } + usage! if numbers.length < 2 + + numbers +rescue ArgumentError, NoMethodError + usage! +end + +def merge_sort(arr) + return arr if arr.length <= 1 + + mid = arr.length / 2 + left = merge_sort(arr[0...mid]) + right = merge_sort(arr[mid..]) + + merge(left, right) +end + +def merge(left, right) + i = 0 + j = 0 + result = [] + + while i < left.length && j < right.length + if left[i] <= right[j] + result << left[i] + i += 1 + else + result << right[j] + j += 1 + end + end + + result.concat(left[i..] || []) + result.concat(right[j..] || []) + result +end + +numbers = parse_input +puts merge_sort(numbers).join(", ")