3. DFS 做unique permutation: given input有duplicate characters。 Given a string s, return all the palindromic permutations (without duplicates) of it. Return an empty list if no palindromic permutation ...

This game takes two words of equal length and sees if it can permute the source word into a the destination word in a certain number of hops. Each hop, the word is only allowed to alter one letter at ...

Backtracking has proven itself to be a universal algorithmic technique that can be applied while solving all kinds of computational problems, from the most primitive (such as counting all possible ...