As per Daily Coding Problem
This problem was asked by Facebook.
Write a function that rotates a list by k elements.
For example, [1, 2, 3, 4, 5, 6] rotated by two becomes [3, 4, 5, 6, 1, 2].
Try solving this without creating a copy of the list.
​How many swap or move operations do you need?

Below, I think can be a way to write the code for this, please suggest the better way-

This problem was asked by Facebook as per Daily Coding Problem.
Given a string and a set of delimiters, reverse the words in the string while maintaining the relative order of the delimiters. For example, given "hello/world:here", return "here/world:hello"
Follow-up: Does your solution work for the following cases: "hello/world:here/", "hello//world:here"

Note :- I don't agree with above Follow-up point as relative order is changing, I think so.
            So either 1st example is correct or the Follow-up example. For below solution I am
            considering first example as the correct one.