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tsnow/vampire_numbers.rb

Created July 21, 2013 13:43
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vampire_numbers.rb
(10000000..99999999). #change to e.g. 1000..9999 for all 4 digit, 100000..999999 for all 6 digit nums
select do |i|
start=i.to_s.split('');
bk= (start.length / 2) - 1;
first = start[0..bk].join('').to_i;
last = start[-(bk+1)..-1].join('').to_i;
next if last > first;
prod = (first * last).to_s.split('');
prod.sort == start.sort;
end
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