You can use a map to store the numbers you've seen. Map lookup is O(1), compared to looking through a list (O(n)). The keys can be the numbers you've seen, the values the list of positions.
Thank you for the suggestion! I'll try it!
Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink.
Hide child comments as well
Confirm
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
You can use a map to store the numbers you've seen. Map lookup is O(1), compared to looking through a list (O(n)). The keys can be the numbers you've seen, the values the list of positions.
Thank you for the suggestion! I'll try it!