Euler11.rb

GRID = "08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48"

#Place Grid in Array
narray = []
for i in 1..400
 #get number
 num = GRID[(i-1)*3,2].to_i
 #set coordinates 
 row = ((i-1)/20).floor
 if i <= 20
  col = i - 1
 else 
  col = i % 20
 end
 #Load to narray
 narray << num
end

print narray
puts ''

prod = []
#Go through each number, Can only check from 3 to 6 o clock
k = 0
narray.each do |n|
 #Set Row and Column
 puts k
 r = (k/20).to_i
 c = k - (20*r)
 puts "Row: " + r.to_s
 puts "Col: " + c.to_s
 #Check Down
 if k < 320
  #Get product of Down 4
  p = 1
  for x in 0..3
   p *= narray[k + (20*x)]
  end
  prod << p
  #Get product of Downright Diag
  if c <= 16
   p = 1
   for x in 0..3
    p *= narray[k + (20*x) + x]
   end
   prod << p
  end
  #Get Downleft Diag if far enough in
  if c >= 3
   p = 1
   for x in 0..3
    p *= narray[k + (20*x) - x]
   end
   prod << p
  end
 end
 #Check Right
 if c <= 16
  p = 1
  for x in 0..3
   p *= narray[k + x]
  end
  prod << p
 end
 #Next k
 k +=1
end

puts prod.max