You can look at competitive programming sites, they are a lot more serious than leetcode/hackerrank https://dmoj.ca/problems/?type=5&show_types=1&order=-points

You can look at competitive programming sites, they are a lot more serious than leetcode/hackerrank https://dmoj.ca/problems/?type=5&show_types=1&order=-points https://dmoj.ca/problems/?type=5&show_types=1&order=-points https://codeforces.com/problemset?order=BY_RATING_DESC&tags=dp https://codeforces.com/problemset?order=BY_RATING_DESC&tags=...