LCS Ruby

.rb

chars = ('a'..'z').to_a
x = []
y = []
5.times {|char| x << chars[rand(26)]}
5.times {|char| y << chars[rand(26)]}
c = Array.new(x.size + 1){Array.new(y.size + 1, 0)}
b = Array.new(x.size + 1){Array.new(y.size + 1, 0)}

def LCS_length(x, y, c, b)
  (1..x.size).each do |i|
    (1..y.size).each do |j|
      if x[i - 1] == y[j - 1]
        c[i][j] = c[i - 1][j - 1] + 1
        b[i][j] = 0
      else
        if c[i - 1][j] >= c[i][j - 1]
          c[i][j] = c[i - 1][j]
          b[i][j] = 1
        else
          c[i][j] = c[i][j - 1]
          b[i][j] = 2
        end
      end
    end
  end
end
def Print_LCS(x, b, i, j)
  return if i == 0 || j == 0
  if b[i][j] == 0
    Print_LCS(x, b, i - 1, j - 1)
    printf("%c ", x[i - 1])
  elsif(b[i][j] == 1)
    Print_LCS(x, b, i - 1, j)
  else
    Print_LCS(x, b, i, j - 1)
  end
end

LCS_length(x, y, c, b)
Print_LCS(x, b, x.size, y.size)