Challengers Hackerrank

save_the_princess.rb

#!/bin/ruby
Position = Struct.new(:x,:y) do
  def ==(pos)
    x == pos.x && y == pos.y
  end
end

class Finder
  def self.princess(grid)
    edge = grid.length - 1
    [0,edge].each do |row|
      [0,edge].each do |col|
        return Position.new(col,row) if grid[row][col] == 'p'
      end
    end
  end

  def self.bot(grid)
    x = y = grid.length / 2
    Position.new(x,y)
  end
end

def displayPathtoPrincess(n,grid)
  princess = Finder.princess(grid)
  bot = Finder.bot(grid)
  path = []

  while bot != princess
    path << if bot.x < princess.x
      bot.x += 1
      "RIGHT"
    elsif bot.x > princess.x
      bot.x -= 1
      "LEFT"
    end

    path << if bot.y < princess.y
      bot.y += 1
      "DOWN"
    elsif bot.y > princess.y
      bot.y -= 1
      "UP"
    end
  end
  path
end

m = gets.to_i
grid = Array.new(m)
(0...m).each do |i|
    grid[i] = gets.strip
end
puts displayPathtoPrincess(m,grid)

save_the_princess2.rb

#!/bin/ruby
Position = Struct.new(:x,:y)

def find_princess(grid)
  grid.each_with_index do |row, y|
    row.each_char do |col|
      return Position.new(row.index(col), y ) if col == 'p'
    end
  end
end


def nextMove(n,r,c,grid)
  bot = Position.new c, r
  princess = find_princess grid
  delta = {
    x: bot.x - princess.x,
    y: bot.y - princess.y
  }

  far = delta.max_by {|_,value| value.abs}

  case far[0]
  when :x
    far[1] < 0 ? "RIGHT" : "LEFT"
  when :y
    far[1] < 0 ? "DOWN" : "UP"
  end
end

n = gets.to_i

r,c = gets.strip.split.map(&:to_i)

grid = Array.new(n)

(0...n).each do |i|
  grid[i] = gets
end

puts nextMove(n,r,c,grid)