A solution (at least I think it's right...) to http://challenge.signpost.com/leveltwo The Ransom Glad you've made it this far, intrepid friend of Max. To tell you a little about ourselves, our goal is to end winter in Chicago. We've read our Ries and plan to start small, with an MVP. We currently have the resources to build a structure covering …

Winter-func.rb

require 'open-uri'


def adj_sum(multi,x,y)
  sum = multi[x][y].to_i

	if x > 0 
		sum += multi[x-1][y].to_i
	end
	if x < 999
		sum += multi[x+1][y].to_i
	end
	if y > 0
		sum += multi[x][y-1].to_i
	end
	if y < 17
		sum += multi[x][y+1].to_i
	end

	sum
end


data = open("http://challenge.signpost.com/static/density.txt")

lines = Array.new

data.each_line {|line| lines << line.split(' ')}


max = 0

line_num = 0

for k in (0...1000)
	for j in (0...18)
		total_people = adj_sum(lines,k,j)
		max = total_people unless max > total_people
	end
end

puts "max is #{max}"

I arrived at the same result using JavaScript--and was told the answer was Wrong.

You should be able to run this from the console in Chrome Developer Tools on the density page:

var data = document.getElementsByTagName('pre')[0].innerHTML.split(' ');

var getAdjacent = function(data, index) {
  var top = data[index-18] - 0 || 0,
    bottom = data[index+18] - 0 || 0,
    left = data[index-1] - 0 || 0,
    right = data[index+1] - 0 || 0,
    center = data[index] - 0 || 0;
  return top + bottom + left + right + center;
}

var max = 0;
for (var i = 0, l = data.length; i < l; i++) {
  var sum = getAdjacent(data, i);
  max = Math.max(max, sum);
}

console.log(max);

Wow, didn't notice you wrote here, Seth. Thanks.

I figured I was right. Thanks for the help.