Add new algorithm with well commented clean code.[C++]

[llucifer97]

Added the new algorithm,s with well commented clean code.[C++]

[jineshparakh]

Can you please assign this to me?

[llucifer97]

U r assigned this issue @jineshparakh

[AparnaJuhi]

@llucifer97 I have added some famous solutions of algo/ds asked in Coding Rounds. Please review my PR.

[sbhavya18]

Kindly assign me this. I will implement this is C++.

[jineshparakh]

@llucifer97 , I wish to contribute by adding some codes on trees.
Should I add them to the graph algorithm folder or make a new one for trees?