And here is my solution. It tries to find first suitable letter
repetition and print the whole word on the screen with the very tight
loop. Suitable repetition exists when distance between identical letters
is an even number greater or equal to four.
#!/usr/bin/env ruby
# Solution to Ruby Quiz #149 (see http://www.rubyquiz.com/quiz149.html)
# by Pawel Radecki (pawel.j.radecki@gmail.com).
require 'logger'
$LOG = Logger.new($stderr)
#logging
#$LOG.level = Logger::DEBUG #DEBUG
$LOG.level = Logger::ERROR #PRODUCTION
NO_LOOP_TEXT = "No loop."
class String
private
def compose_word_loop_array (index1, index2)
a = Array.new(self.length) {|i| Array.new(self.length, " ") }
i=0
while (i<index1)
a[1][i] = self[i].chr
i+=1
end
#repeated letter, first occurrence, loop point
a[1][index1]=self[index1].chr
i=index1+1
boundary = (index2-index1)/2+index1
while(i<boundary)
a[1][i] = self[i].chr
i+=1
end
i=index2-1; j=index1
while(i>boundary-1)
a[0][j] = self[i].chr
j+=1; i-=1
end
i=index2+1; j=2
while (i<self.length)
a[j][index1] = self[i].chr
i+=1; j+=1
end
#cut all empty rows
a.slice!(j..self.length-1)
a
end
public
def word_loop
if (self.length<=4)
return NO_LOOP_TEXT
end
s = self
index1 = index2 = nil
#find repeated letter suitable for a loop by
#taking 1st letter and comparing to 5th, 7th, 9th, 11th, etc.
#taking 2nd letter and comparing to 6th, 8th, 10th, 12th, etc.
#taking 3rd letter and comparing to 7th, 9th, 11th etc.
#etc.
i = 0
while i<s.length-1
j=i+4
while j<s.length
$LOG.debug("i: #{i}")
$LOG.debug("j: #{j}")
$LOG.debug("s[i]: #{s[i].chr}")
$LOG.debug("s[j]: #{s[j].chr}")
$LOG.debug("\n")
if s[i] == s[j]
return compose_word_loop_array(i, j)
end
j+=2
end
i+=1
end
return NO_LOOP_TEXT
end
end
USAGE = <<ENDUSAGE
Usage:
word_loop <message>
ENDUSAGE
if ARGV.length!=1
puts USAGE
exit
end
input_word = ARGV[0]
a = input_word.word_loop
if a.instance_of? Array
a.each {|x| puts x.join("") }
else
print a
end
exit
···
--
Paweł Radecki
m: +48 695 34-64-76
e: pawel.j.radecki@gmail.com
w: http://radeckimarch.blogspot.com/
