AdventOfCode/spirallingdistance.rb

###
# Part 1
###


input = 325489

side_length = Math.sqrt(input).ceil                     ## 571
num_at_level = side_length**2                       ## 326041
diff = num_at_level - input                             ## 552

steps_req = diff % (side_length - 1)                ## 552
to_center = (side_length-1) / 2                     ## 285
to_mid_of_row = ((side_length / 2) - steps_req).abs ## 267
solution = to_center + to_mid_of_row                ## 552
puts "Pls correct yes: " + solution.to_s


###
# Part 2
###
# Fuck it, bruteforcing

input = 325489

def look_around(x,y,spiral)
  result = 0
  (y-1...y+2).each do |y_val|
    (x-1...x+2).each do |x_val|
      result += spiral[[x_val,y_val]]
    end
  end
  result
end

def increment_spiral(x,y,spiral)
  spiral[[x,y]] = look_around(x,y,spiral)
end

def pls(input)
  result = 0
  spiral = Hash.new 0
  spiral[[0,0]],i,j = 1,0,0
  inf = Float::INFINITY
  (1..inf).step(2) do |s|
    (0...s).each do
      i+=1
      spiral[[i,j]] = look_around(i,j,spiral)
      if spiral[[i,j]] > input then
        result = spiral[[i,j]]
        puts result
        break
      end
    end
    if result != 0 then break end
    (0...s).each do
      j-=1
      spiral[[i,j]] = look_around(i,j,spiral)
      if spiral[[i,j]] > input then
        result = spiral[[i,j]]
        puts result
        break
      end
    end
    if result != 0 then break end
    (0...(s+1)).each do
      i-=1
      spiral[[i,j]] = look_around(i,j,spiral)
      if spiral[[i,j]] > input then
        result = spiral[[i,j]]
        puts result
        break
      end
    end
    if result != 0 then break end
    (0...(s+1)).each do
      j+=1
      spiral[[i,j]] = look_around(i,j,spiral)
      if spiral[[i,j]] > input then
        result = spiral[[i,j]]
        puts result
        break
      end
    end
    if result != 0 then break end
  end
end
pls(325489)