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askl56/last_digits.rb Secret

Created December 13, 2015 15:55
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last_digits.rb
LAST_DIGITS = [
[0],
[1],
[2, 4, 8, 6],
[3, 9, 7, 1],
[4, 6],
[5],
[6],
[7, 9, 3, 1],
[8, 4, 2, 6],
[9, 1]
]
def last_digit(n1, n2)
return 1 if n2 == 0
digits = LAST_DIGITS[n1 % 10]
digits[(n2 - 1) % digits.length]
end
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