Swapping By call by value.... Help !!!

Question

https://code.sololearn.com/cf43CfC6Fm6w/?ref=app

It is not swapping the value...
please help

Answer 1

Call by value won't work. Use pointer (call by reference). Pass the memory addresses of variables to function.
https://code.sololearn.com/cKKCGqHSyvMb/?ref=app

Answer 2

seems that iostream.h doesn't exist