whiteboard wednesday spiral solution

spiral.rb

require 'byebug'
spiral_arr = [
  [1,2,3,4],
  [5,6,7],
  [8,9,10,11],
  [12,13,14]
]

@held_arr = nil

@dirs = [:right, :down, :left, :up]
@dirNum = 0
@currentDir = @dirs[@dirNum]

@result = []

def turnRight
  if @dirNum == @dirs.length - 1
    @dirNum = 0
  else
    @dirNum += 1
  end

  @currentDir = @dirs[@dirNum]
end

def goRight(arr)
  while arr[0].any?
    @result.push arr[0].shift
  end

  arr.shift
  turnRight()

  spiral(arr)
end

def goDown(arr)
  arr.each do |a|
    @result.push a.pop
  end

  turnRight()
  spiral(arr)
end

def goLeft(arr)
  while arr[-1].any?
    @result.push arr[-1].pop
  end

  # remove last array
  arr.pop
  turnRight()
  spiral(arr)
end

def goUp(arr)
  arr.reverse.each do |a|
    @result.push a.shift
  end

  turnRight()
  spiral(arr)
end

def spiral(arr)
  # create a copy of array so we dont munge the original
  @held_arr = Array.new(arr) if !@held_arr
    
  if arr.empty?
    return @result
  else
    case @currentDir
    when :right
      goRight(@held_arr)
    when :down
      goDown(@held_arr)
    when :left
      goLeft(@held_arr)
    when :up
      goUp(@held_arr)
    end
  end
end

expected_result = [1,2,3,4,7,11,14,13,12,8,5,6,10,9]

r = spiral(spiral_arr)
if r == expected_result
  puts 'you wun'
else
  puts 'YOU BLEW IT'
  puts "expected: #{expected_result}"
  puts "result: #{r}"
end

coding interview practice competition w/ friends ... was done as quickly as possible to beat them. sorry for the camelCase, clearly had been doing too much CoffeeScript at the time