What does it mean "return all groups"? But the return result is vector<string>? How can we return all groups?

Question

What does it mean "return all groups"? But the return result is vector? How can we return all groups? I mean, for example, we have such vector ["dog","cat","god","tac"]. What should I return?

Answer 1

It means return all group of anagrams being flatten into one single list.

For the input ["dog","cat","god","tac"], it should return: ["dog","cat","god","tac"], as dog and god are one group of anagrams, and cat and tac are another group of anagrams.

I will probably change the return format to a more intuitive manner sometime in the future, such as:

[
  ["dog", "god"],
  ["cat", "tac"]
]

Until this change happens, you will have to deal with the slightly confusing way of returning a flatten list, which should not affect the algorithm itself.