jubishop

def _is_interleave(s1, s2, s3)
  return s2 == s3 if (s1.empty?)
  return s1 == s3 if (s2.empty?)
  return false if ($dp1[s1] == s3)
  if (s1[0] == s3[0])
    return true if _is_interleave(s1[1..-1], s2, s3[1..-1])
  end
  if (s2[0] == s3[0])
    return true if _is_interleave(s1, s2[1..-1], s3[1..-1])
  end

jubishop

# @param {Integer} n
# @return {TreeNode[]}
def generate_trees(n, vals = (1..n).to_a)
  return [] if vals.empty?
  return [TreeNode.new(vals.first)] if (vals.length == 1)

  nodes = Array.new
  all_rights = generate_trees(n, vals[1...vals.length])
  all_rights.each { |right|
    node = TreeNode.new(vals.first)

jubishop

def num_search(string, ans)
  if (string.empty?)
    ans[:count] += 1
    return
  end
  return if string[0] == "0"
  num_search(string[1..-1], ans)
  if (string.length > 1 and (string[0].to_i < 2 or (string[0].to_i == 2 and string[1].to_i < 7)))
    num_search(string[2..-1], ans)
  end

jubishop

class String
  include Enumerable

  def each
    each_char { |char| yield char }
  end
end

def split_parts(string)
  parts = Array.new

jubishop

class String
  include Enumerable

  def each
    each_char { |char| yield char }
  end
end

def compress_string(string)
  string.chunk{|x|x}.map { |char, ary| ary.length > 1 ? "#{char}#{ary.length}" : char }.join('')

jubishop

# Usage:
# (min..max) { |x| x <=> target } => Integer or nil
class Range
  def binary_search
    left, right = min, max
    while (left <= right)
      middle = left + ((right - left) / 2)
      result = yield middle
      if (result == 0)

jubishop

def match(board, char, row, col)
  return false if row < 0 or row >= board.length
  return false if col < 0 or col >= board.first.length
  return board[row][col] == char
end

def _exist(board, word, row, col)
  return true if word.empty?
  [[row-1, col], [row+1, col], [row, col-1], [row, col+1]].each { |cur_row, cur_col|
    if (match(board, word[0], cur_row, cur_col))

jubishop

def min_distance(from_word, to_word)
  return 0 if from_word == to_word
  count = 0
  words = [from_word]
  loop {
    new_words = Array.new
    words.uniq.each { |word|
      index = 0
      rindex = -1
      index += 1 until (word[index] != to_word[index])

jubishop

def min_distance(from_word, to_word)
  count = 0
  words = [from_word]
  loop {
    return count if (words.include?(to_word))
    new_words = Array.new
    words.each { |word|
      index = 0
      rindex = -1
      index += 1 until (word[index] != to_word[index])

jubishop

def spacers(num, divisor)
  ans = Array.new
  until (num == 0)
    space = num / divisor
    ans.push(space)
    num -= space
    divisor -= 1
  end
  return ans.reverse
end