cfd code using mac cormack scheme
 

Hello,
I've written a cfd code. I used mac cormack scheme. But, the answers are not what I've expected.
When CFL=1, it should give exact solution. But, it's amplitude is damped and its charactristic lines changed their directions,by the way the initial condition is sin(pi(x)) when x is between 0 and 2 and 1 when x is between 2 and 5.

Do I miss any step? How can I get the exact solution I've expected?
Thanks in advance

geometry dash scratch