euler18_67.rb

require_relative 'euler_util'
$triangle = %Q{
    75
    95 64
    17 47 82
    18 35 87 10
    20 04 82 47 65
    19 01 23 75 03 34
    88 02 77 73 07 63 67
    99 65 04 28 06 16 70 92
    41 41 26 56 83 40 80 70 33
    41 48 72 33 47 32 37 16 94 29
    53 71 44 65 25 43 91 52 97 51 14
    70 11 33 28 77 73 17 78 39 68 17 57
    91 71 52 38 17 14 91 43 58 50 27 29 48
    63 66 04 68 89 53 67 30 73 16 69 87 40 31
    04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
}

def maxRoutine(ary2d)
  height = ary2d.size
  (height-2).downto(0).each do |h|
    (0..h).each do |idx|
      ary2d[h][idx] += [ary2d[h+1][idx],ary2d[h+1][idx+1]].max
    end
  end
  ary2d[0]
end

def result
  e18 = maxRoutine(String2Num.numAry($triangle))
  numStr = IO.read("triangle.txt")
  ary = String2Num.numAry(numStr)
  e67 = maxRoutine(ary)
 "e18 = #{e18}\ne67 = #{e67}"
end

puts result