## Problem <br> :::spoiler **Optimal Space & Time Complexity** ``` - Time complexity: - Space complexity: ``` ::: <br> <hr/> ## Solutions :::spoiler 東 ```javascript= ``` ::: <br> :::spoiler Hao ```javascript= ``` ::: <br> :::spoiler YC ```javascript= ``` ::: <br> :::spoiler SOL ```javascript= ``` ::: --- ## Supplement / Discussion ### 東 ### Hao ### YC ### SOL