exploding_dice.rb

# Messing with some experimental statistical analysis for infinitely exploding dice

def roll_die(d)
  rand(d) + 1
end

def roll_exploding_die(d)
  r = roll_die(d)
  if r == d
    r + roll_exploding_die(d)
  else
    r
  end
end

def roll_exploding_dice(n, d)
  (1 .. n).map do
    roll_exploding_die(d)
  end
end

def roll_success(d, s)
  r = roll_die(d)
  if r == d
    1 + roll_success(d, s)
  elsif r >= s
    1
  else
    0
  end
end

def roll_successes(n, d, s = d - 2)
  sum = 0
  n.times do
    sum += roll_success(d, s)
  end
  sum
end

5_000_000.times do
  p roll_successes(6, 6)
end