The problem is that within an interview context, many times one is expected to just come up with a perfect solution within a short timeframe. It's possible to

The problem is that within an interview context, many times one is expected to just come up with a perfect solution within a short timeframe. It's possible to solve these on the fly, but you're at a disadvantage compared to people who have done hundreds of these problems, pattern match to the closest leetcode problem, then immediately write the optimal solution on the board.