python - how do I multiply integers in a set?

Question

You are given a sequence of positive ints where every element appears three times, except one that appears only once (let's call it x) and one that appears only twice (let's call it y). Your task is to find x * x * y.

e.g. arr = [1,1,1,2,2,2,3,3,4] -> 4 x 4 x 3

I have written some code below. I have a question regarding the final part of the code- so after the completion of the loop, there should be one integer left in seen_once and one integer left in seen_twice, but how do I then multiply these numbers, as they are now sitting in a set()?

 def Missing_Values(arr):
     seen_once = set()
     seen_twice = set()
     seen_thrice = set()

     for i in arr:
         if i not in seen_once or seen_twice or seen_thrice:
             seen_once.add(i)

         elif i in seen_once:
             seen_twice.add(i)
             seen_once.remove(i)

         elif i in seen_twice:
             seen_thrice.add(i)
             seen_twice.remove(i)

     return seen_once*seen_once*seen_twice

 Missing_Values(arr)

question from:https://stackoverflow.com/questions/66063813/how-do-i-multiply-integers-in-a-set

Answer 1

One way would be to pop the values.

x = seen_once.pop()
y = seen_twice.pop()
return x * x * y