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@jfarmer

jfarmer/rot_n_jesse.rb

Forked from Katzy/ROTN
Last active Aug 29, 2015
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def rot_n_char(char, rot_by)
fail ArgumentError, "First argument must be a 1-letter String (got `#{char}')" unless char.length == 1
case char
when ('a'..'z')
((char.ord - 'a'.ord + rot_by) % 26 + 'a'.ord).chr
when ('A'..'Z')
((char.ord - 'A'.ord + rot_by) % 26 + 'A'.ord).chr
else
char
end
end
def rot_n(string, rot_by)
string.chars.map { |char| rot_n_char(char, rot_by) }.join
end
if __FILE__ == $0
p rot_n("The quick brown fox jumps over the lazy dog.", 14) == "Hvs eiwqy pfckb tcl xiadg cjsf hvs zonm rcu."
%w(abcdef bcdefg cdefgh defghi).each_with_index do |output_str, i|
input_str = "abcdef"
p rot_n(input_str, i) == output_str
p rot_n(input_str.upcase, i) == output_str.upcase
p rot_n(input_str + input_str.upcase, i) == output_str + output_str.upcase
end
end
def rot_n(string, n)
rotn_ary = []
n = n % 26
n > 13 ? n2 = (26 - n) : n2 = n # n2 for numbers greater than 13
string.each_char do |char|
if char.ord < 65 || (char.ord > 90 && char.ord < 97) || char.ord > 122
rotn_ary.push(char)
elsif "z".ord - n >= char.downcase.ord && "z".ord - char.downcase.ord + n >= 26
rotn_ary.push((char.ord + n).chr)
else
rotn_ary.push((char.ord - n2).chr)
end
end
rotn_ary.join
end
if __FILE__ == $0
p rot_n("People who eat beef are the enemy of vegetarians.", 22)
p rot_n("The quick brown fox jumps over the lazy dog.", 14) == "Hvs eiwqy pfckb tcl xiadg cjsf hvs zonm rcu."
end
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