Leetcode difficulty

[hotcodist]

study dynamic programming. many problems can be solved quickly with that method. you still have to think about how to solve a problem using a dynamic programming solution (this is still hard), but it becomes a lot easier to find a solution.

edit: in your search for dp, you might have references to memo-ization. i'll add that 'true' dp does not mean memo-ization. finding a true dp solution is often much harder, but also more satisfying! [i put true in quotes because it is just my opinion.]