It's no bad thing to import modules if they get the job done! There's a time and a place for code golf. That said - with the distance of several years' hindsight - I should probably have added a short comment.

Really nice! I saw someone else use a for-loop with an xor operator (i.e. "^") which is similar and doesn't need an import. I like this the best because it is O(n) and it is very clean. It's a bit more arcane than the simplest solution, but for large values of N this is definitely the right approach.

Good work :)

Oh, I like this one! It's linear time, unlike many of the other solutions. Well done!!

321

00

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I also was getting "value is not what was expected" in the JAvaScript test cases. However, my logic was sound as I was getting the right value and the same value I got with Python. Value = 23 for the submitted solutions. Also there are no JavaScript client solutions -- though I am not sure what the difference is between local and submit testing -- speed maybe?

I like the thinking here, however you iterate over the list three times instead of just one, although you do avoid all comparisons :)

Non, "If such an element is found, some immediately returns true. Otherwise, ..."

some returns -1

right?