Problem:
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Areas on the Cross-Section Diagram

Your task is to simulate a flood damage.

For a given cross-section diagram, reports areas of flooded sections.

Assume that rain is falling endlessly in the region and the water overflowing from the region is falling in the sea at the both sides.
For example, for the above cross-section diagram, the rain will create floods which have areas of 4, 2, 1, 19 and 9 respectively.

Input

A string, which represents slopes and flatlands by '/', '\' and '_' respectively, is given in a line. For example, the region of the above example is given by a string "\\///\_/\/\\\\/_/\\///__\\\_\\/_\/_/\".

output

Report the areas of floods in the following format:

$A$

$k$ $L_1$ $L_2$ ... $L_k$

In the first line, print the total area $A$ of created floods.

In the second line, print the number of floods $k$ and areas $L_i (i = 1, 2, ..., k)$ for each flood from the left side of the cross-section diagram. Print a space character before $L_i$.

Constraints

$1 \leq$ length of the string $\leq 20,000$

Sample Input 1

\\//

Sample Output 1

4
1 4

Sample Input 2

\\///\_/\/\\\\/_/\\///__\\\_\\/_\/_/\

Sample Output 2

35
5 4 2 1 19 9

Solution in Ruby (judge verdict: Accepted)

class MyStack
  def initialize(max)
    @top = 0
    @max = max
    @s = Array.new(max)
  end

  def is_empty?
    @top == 0
  end

  def is_full?
    @top >= (@max -1)
  end

  def push(x)
    if is_full?
      raise "overflow"
    end
    @top += 1
    @s[@top] = x
  end

  def pop
    if is_empty?
      raise "underflow"
    end
    @top -=1
    @s[@top+1]
  end

  def dump
    puts @s
  end

  def print
    results = []
    while (!is_empty?) do
      results << pop[1]
    end
    pools = results.empty? ? '' : ' ' + results.reverse.join(' ')
    puts results.length.to_s + pools
  end
end

inputs = gets.split('')

s1 = MyStack.new(20000)
s2 = MyStack.new(10000)
total = 0
is_contiguous = false
inputs.each_with_index do |x, i|
  case x
  when "\\"
    s1.push(i)
    is_contiguous = false
  when "/"
    if s1.is_empty?
      next
    end

    position = s1.pop()
    area = i - position
    total += area
    total_prev_area = 0
    stack_position = position + 1
    while (!s2.is_empty?)
      prev_position, prev_area = s2.pop()
      if prev_position < position
        s2.push([prev_position, prev_area])
        break
      end
      total_prev_area += prev_area
      stack_position = prev_position
    end

    s2.push([stack_position -1, total_prev_area + area])
  when "_"
    next
  end
end

puts total
# s2.dump
s2.print