FizzBuzz
http://www.codinghorror.com/blog/archives/000781.html
It is about how a lot of job applicants have a hard time actually programming. My friend and I were amused by it and started going back and forth with different implementations until it got to this point.
The problem is:
'Write a program that prints the numbers from 1 to 100. But for multiples of three print "Fizz" instead of the number and for the multiples of five print "Buzz". For numbers which are multiples of both three and five print "FizzBuzz".'
Now, it can be done like this:
1 2 1.upto(100) { |n| puts n % 3 == 0 ? n % 5 == 0 ? "fizzbuzz" : "buzz" : n % 5 == 0 ? "fizz" : n }
But, this is what I ended up with, which turns out actually to be faster and obviously far more flexible:
1 2 class FizzBuzz 3 4 def initialize(start_number, end_number) 5 @starting = start_number 6 @ending = end_number 7 @phrase_multiples = [] 8 end 9 10 def add_phrase_multiple(phrase, multiple) 11 @phrase_multiples << [phrase, multiple] 12 end 13 14 def print_phrases 15 fb_array = process_phrases 16 puts fb_array.collect { |e| e[1] || e[0] }.join("\n") 17 end 18 19 private 20 21 def process_phrases 22 rarray = Array.new(@ending - @starting) 23 rarray = rarray.each_with_index { |item, i| rarray[i] = [i + @starting, item] } 24 @phrase_multiples.each { |pm| fill_multiples(rarray, pm[1], pm[0]) } 25 rarray 26 end 27 28 def fill_multiples(fill_array, the_int, printed) 29 (the_int - (fill_array[0][0] % the_int)).step(fill_array.size - 1, the_int) do |i| 30 fill_array[i][1] = fill_array[i][1].to_s + printed.to_s 31 end 32 end 33 34 end 35 36 fb = FizzBuzz.new(1,100) 37 fb.add_phrase_multiple('fizz', 3) 38 fb.add_phrase_multiple('buzz', 5) 39 fb.print_phrases