ruby-golf

gistfile1.rb

# using Ruby 1.9.2

# Hole 1, 41 chars
def fizzbuzz(n)
  "#{n%3<1&&f=:Fizz;n%5<1?"#{f}Buzz":f||n}"
end
# Same as Cyrus's solution, optimized

p fizzbuzz(3)  # => "Fizz"
p fizzbuzz(10) # => "Buzz"
p fizzbuzz(45) # => "FizzBuzz"
p fizzbuzz(31) # => "31"

# ----------------
# Hole 2, 39 chars
def caesar(s,i)
  s.bytes.map{|b|97+(b-97+i)%26}.pack'c*'
end
# One more of the same length:
# s.bytes.map{|b|(97+(b-97+i)%26).chr}*''

p caesar("hello",3)  # => "khoor"
p caesar("hello",0)  # => "hello"
p caesar("khoor",-3) # => "hello"

# ----------------
# Hole3, 91 chars
def play(f)
  m=%w(Rock Paper Scissors);c=rand(3);u=m.index(f)||c-1;[m[c],%w(Draw Win Lose)[(u-c)%3]]*','
end

p play("Rock")     # => "Rock,Draw"
p play("Paper")    # => "Rock,Win"
p play("Scissors") # => "Rock,Lose"
p play("Soap")     # => "Paper,Lose"

# ----------------
# Hole 4, 33 chars
def counter(s,i)
  s.scan(/#{Regexp.quote i}/i).size
end
# This is sufficient if only alphanumeric chars allowed:
# s.scan(/#{i}/i).size

p counter("Banana","a") # => 3
p counter("RubySource provides advice, tutorials, commentary, and insight into the Ruby and Rails ecosystem","ruby") # => 2

# ----------------
# Hole 5, 38 chars
def swingers(a)
  x,y=a.shuffle.transpose;x.zip y.rotate
end

p swingers([["Homer","Marge"],["Micky","Minnie"],["Fred","Wilma"],["Peter","Lois"],["George","Judy"]])
# => [["Homer","Wilma"],["Micky","Lois"],["Fred","Judy"],["Peter","Marge"],["George","Minnie"]]