Ooyala Second Test

ooyala-second-test.rb

# 1
def reverse(val = "")
  val.split.reverse.join(" ")
end

# 2
def first_missing(val = [])
  return 1 if val.select {|x| x > 0}.empty?
  return val.select {|x| x > 0}.inject(&:+) + 1 if val.select {|x| x > 0}.size == 1
  counter = val.uniq.select {|x| x > 0}.sort.min
  val.uniq.select {|x| x > 0}.sort.each do |item|
    return counter if item != counter
    counter+=1
  end
  val.uniq.select {|x| x > 0}.sort.max + 1
end

# 3
# val = [[0,0,1], [1,0,1], [1,1,0]]
def island_size(val = [])
  max = 0
  counter = 0
  
  return 0 if val.empty?

  val.each_with_index do |row, index|
    for col in 0..val.size - 1
      counter = 0 if row[col] == 0
      
      if row[col] == 1
        counter += 1 + north(val, col, index - 1) + south(val, col, index + 1)
        max = counter if counter > max
      end
    end
    counter = 0
  end
  max
end

def north(val = [], col = 0, index = 0)
  return 0 if index < 0
  return 0 if val[index][col] == 0
  return val[index][col] + north(val, col, index - 1) if val[index][col] == 1
  return 0
rescue => e
  0
end

def south(val = [], col = 0, index = 0)
  return 0 if index > val.size - 1
  return 0 if val[index][col] == 0
  return val[index][col] + south(val, col, index + 1) if val[index][col] == 1
  return 0 
rescue => e
  0
end

# 4
def largest_combination(val = [])
  val.permutation(val.size).to_a.map {|x| x.join.to_i}.max
end