AlgoExpert problems are in 5 different categories: easy, medium, hard, very hard and extremely hard. Example of easy problems include node depths, product sum, Nth Fibonacci, and palindrome check. Some medium problems include three number sum, smallest difference, group anagrams, balanced brackets, and permutations. Hard problems include summary sort, water area, and Boggle board. Very hard problems include apartment hunting, palindrome partitioning and merge sort. Extremely hard includes square of zeroes and right smaller than. Learn more about AlgoExpert problems in today's post.