euler11.rb

grid = [
%w[08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08],
%w[49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00],
%w[81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65],
%w[52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91],
%w[22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80],
%w[24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50],
%w[32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70],
%w[67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21],
%w[24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72],
%w[21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95],
%w[78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92],
%w[16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57],
%w[86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58],
%w[19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40],
%w[04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66],
%w[88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69],
%w[04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36],
%w[20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16],
%w[20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54],
%w[01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48]]
#make numbers
20.times do |j|
	grid[j].map!  {|i| i = i.to_i}
end
#check products going across
max_prod = 0
row = 0
col = 0
j = 0
while j<20
	x = grid[j]
	i = 0
	while i <17
		prod = x[i]*x[i+1]*x[i+2]*x[i+3] 
		if prod > max_prod
			max_prod = prod
			col = i
			row = j
			puts "#{max_prod} #{col} #{row}"
			puts "#{x[i]} #{x[i+1]} #{x[i+2]} #{x[i+3]}"
		end
		i += 1
	end
	j += 1
end

puts "### NOW GOING DOWN ###"

i = 0
while i < 20
	j = 0
	while j < 17
		prod = grid[j][i]*grid[j+1][i]*grid[j+2][i]*grid[j+3][i]
		if prod > max_prod
			max_prod = prod
			puts "#{max_prod} #{i} #{j}"
			puts "#{grid[j][i]} #{grid[j+1][i]} #{grid[j+2][i]} #{grid[j+3][i]}"
		end
		j += 1
	end
	i += 1
end

puts max_prod

puts "### NOW GOING DOWNRIGHT ###"

j = 0
i = 0
cross = 0
while j < 17
	i = 0
	while i < 17
		prod = grid[j][i]*grid[j+1][i+1]*grid[j+2][i+2]*grid[j+3][i+3]
		if prod > cross
			cross = prod
			puts "#{cross} #{i} #{j}"
			puts "#{grid[j][i]} #{grid[j+1][i+1]} #{grid[j+2][i+2]} #{grid[j+3][i+3]}"
		end
		i += 1
	end
	j += 1
end

puts "### NOW GOING DOWNLEFT ###"
cross = 0
j = 0
while j < 17
	i = 3
	while i < 20
		prod = grid[j][i]*grid[j+1][i-1]*grid[j+2][i-2]*grid[j+3][i-3]
		if prod > cross
			cross = prod
			puts "#{cross} #{i} #{j}"
			puts "#{grid[j][i]} #{grid[j+1][i-1]} #{grid[j+2][i-2]} #{grid[j+3][i-3]}"
		end
		i += 1
	end
	j += 1
end