Lexicographic next string

In this article, we are going to find the lexicographic next string for the given string.

What is lexicographic next string?

Lexicographic next string for a given string is the string whose rank is just 1 more than that for the current string.
For e.g.:- If we have to find the lexicographic next string of ABC then it will be ACB as it will be the next in lexicographic order as the rank of ACB is 2 and that of ABC is 1.

Some approaches :-

One approach is to find all the permutations which can be ...