Problem of the Day
A new programming or logic puzzle every Mon-Fri

Comments:

• Anonymous - 10 years, 9 months ago

  2^15

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• Zing - 10 years, 9 months ago

  17! / (2! 5! 3! 2!) = 123502579200

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• heartinpiece - 10 years, 9 months ago

  Yup, I came up with this answer, just that I forgot the spaces, and thus had 15!/(2!5!3!) Which is semantically wrong :)

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• Carlos - 10 years, 9 months ago

  Don't be stupid as i was and read "UNIQUE permutations", the answer is indeed: 17! / (2 * 2 * 5! * 3!)

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• Shay - 10 years, 9 months ago

  This problem is really ill-phrased... is it permutation of characters? of words? does it include whitespaces?

  Disappointing qotd...

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• Anonymous - 10 years, 9 months ago

  This was my thought. Really poorly defined question. An answer that has to be accepted is 6.

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• tehMagik - 10 years, 9 months ago

  for the sake of coding, the # of permutations:

  def FindNumberOfPermutations(word):
      dividend = math.factorial(len(word))
      divisor = 1
      letterCount = CountCharacters(word).values()
      for count in letterCount:
          divisor = divisor * math.factorial(count)
      return dividend / divisor
  
  def CountCharacters(word):
      letters = {}
      for letter in word:
          if letter not in letters:
              letters[letter] = 1
          else:
              letters[letter] += 1
      return letters
  
  
  permutationCount = FindNumberOfPermutations("Hello world hello")
  

  print(permutationCount)

  Finding all the actual permutations: def FindPermutations(originalWord, currWord=""): global permList if len(originalWord) == 1: currWord += originalWord permList.append(currWord) return for i in range(0,len(originalWord)): perm = currWord + originalWord[i] FindPermutations(originalWord[0:i]+originalWord[i+1:], perm)

  def RemoveDuplicates(item):
      return list(set(item))
  

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• tehMagik - 10 years, 9 months ago

  yeah...it'd be nice if we could just throw <code> in there instead of having to spam spaces. captcha is pretty damn annoying too.

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• Max Burstein - 10 years, 9 months ago

  I'm working on getting a more advanced version of markdown implemented (similar to Github's) which will fix the indentation issue. Authentication is also on the todo list so you won't need to fill in a captcha each time. Hopefully I'll get some time this weekend to knock out a few things.

  Thanks for your submission!

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• tehMagik - 10 years, 9 months ago

  cool, thanks!

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• Jubyjoo - 10 years, 9 months ago

  Hit em up with some of this:

  #!/usr/bin/env python3
  
  import itertools
  
  
  def gap(s, ind):
      """
      print string *s* without letter at index *ind*
      """
      g = s[:ind] + s[ind+1:]
      return g
  
  def distribute(letter, rest_list):
      """
      *rest_list* is list of strings, *letter* is string length 1, append *letter* in front of each of *rest_list*
      return resulting list same length
      """
  
      acc = []
      for i in rest_list:
          n = letter + "".join(i)
          acc.append(n)
      return acc
  
  def permute(s):
      if len(s) <= 1:
          return list(s)
      else:
          acc = []
          for i in range(len(s)):
              acc.append( distribute(s[i],
                                     permute(gap(s,i))))
          # flatten list of lists here
          merged = list(itertools.chain.from_iterable(acc))
          return merged
  
  s = "Hello world hello"
  ret = permute(s)
  for i in ret:
      print(i)
  

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