Quiz 113

ruby-talk
1

From: "Aleksandr Lossenko" <aleksandr.lossenko@gmail.com>
Date: February 10, 2007 1:50:46 PM CST
To: submission@rubyquiz.com
Subject: quiz 113
Reply-To: Aleksandr.Lossenko@gmail.com

Hello,

here are some solutions for the quiz:

1) Anagrams (considering that the first word is also an anagram of itself)
# delete every string that is not anagram of the first string
quiz.delete_if {|x| x.split('').sort.join != quiz[0].split('').sort.join}

2) Convert an Array of objects to nested Hashes
# pop 2 elements, make a hash from them, and push the hash back. when there is only 1 element, the hash is ready
quiz << {quiz.pop => quiz.pop}.invert while(quiz.length >1); quiz.pop

3) Provided with an open File object, select a random line of content.
# lineno gives the number of lines. use the random function and get the line
quiz.readlines[rand(quiz.lineno)]

4) Shuffle array
# take a random element and push it to the top
quiz.size.downto(1) { |n| quiz << quiz.delete_at(rand(n)) };

5) wondrous number
# start with the array containing the first wondrous number and go from there
a=[quiz]; a << (a.last%2==1 ? a.last*3+1 : a.last/2) while a.last!=1

Best Regards,
Aleksandr Lossenko

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