prob11

prob11.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

#prob11
file = open("prob11.txt","r")

grid = Array.new(20).map!{ Array.new( 20, 0 ) }
20.times  do |i|
  line = file.gets
  line.chomp!
  grid[i] = line.split
end

grid.each do |line|
  print line,"\n"
end

max = 1
#横列
20.times do |j|
  (20-3).times do |i|
    tmp = grid[j][i].to_i*grid[j][i+1].to_i*grid[j][i+2].to_i*grid[j][i+3].to_i
    if(tmp>max)
      max=tmp
    end
  end
end

#縦列
20.times do |j|
  (20-3).times do |i|
    tmp = grid[i][j].to_i*grid[i+1][j].to_i*grid[i+2][j].to_i*grid[i+3][j].to_i
    if(tmp>max)
      max=tmp
    end
  end
end

#右下がり列
(20-3).times do |j|
  (20-3).times do |i|
    tmp = grid[j][i].to_i*grid[j+1][i+1].to_i*grid[j+2][i+2].to_i*grid[j+3][i+3].to_i
    if(tmp>max)
      max=tmp
    end
  end
end

#左下がり列
(20-3).times do |j|
  (20-3).times do |i|
    tmp = grid[j][i+3].to_i*grid[j+1][i+2].to_i*grid[j+2][i+1].to_i*grid[j+3][i].to_i
    if(tmp>max)
      max=tmp
    end
  end
end

p max