[eachro]

Leetcode is actually quite good for this. You can find problems to do by topic and the process of doing the easy -> medium problems will get you pretty far in the way of the standard topics (greedy, dynamic programming, divide/conquery, graph search, fundamental data structures and so on).

[deprecative]

Anecdotal in the other way, Leetcode didn't help me at all trying to learn anything. If I knew algorithms and all that went with it/them I'd probably be able to get something out of those exercises.