zebulanmcranahn on Python Multiple Assignment Is a Puzzle

Comment on Python Multiple Assignment Is a Puzzle parent

  def firstMissingPositive(A):
      try:
          for x in range(1, max(A)+1):
              if x not in A: return x
      except: return A

  def firstMissingPositive(A):
      try: return next(x for x in range(1, max(A)+1) if x not in A)
      except: return A

Two above return:

  print(firstMissingPositive([4,2,5,7,1])) # 3
  print(firstMissingPositive([4,100]))     # 1
  print(firstMissingPositive([]))          # []
  print(firstMissingPositive([5]))         # 1

I wasn't sure what [5] or [] were supposed to return so maybe I'm still wrong? Had never heard of this question before, thought I'd try it out.

Thanks for the reply, very informative.

TheLoneWolfling 12y

You really should change "except" to "except ValueError" there.

Also, I suggest first converting A to a set. Just "A = set(A)" would work.

yeukhon 12y

HN is not really for code review, but why are you using try and except here??

TheLoneWolfling 12y

Python is designed for it, and it makes it cleaner, so why not?

EAFP: Easier to ask for forgiveness than permission

That being said, just a blanket except is a bad idea.

zebulanmcranahn 12y

Thanks for the ValueError tip. I added it as well as a TypeError just in case the input comes in as a string. My skills are beginner level at best, tips like yours help a lot!

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