Can someone tell me where did I go wrong.it isn't executing..ND also tell the reason as to y it is not executing.

Question

https://code.sololearn.com/c4xpCs0wPqkb/?ref=app

Answer 1

the main methode is in the class you making a object from

Answer 2

This, in principle, functions:
https://code.sololearn.com/ce0iC2e0T1Jd/?ref=app

About swapping, well, you choosed just a language that passes everything by value, not by referente.
One way is to emulate a reference class:
https://stackoverflow.com/questions/5614562/how-to-do-the-equivalent-of-pass-by-reference-for-primitives-in-java/5614650#5614650