Why is it not working ?

Question

A program to reverse an arbitrary sized array in C
https://code.sololearn.com/cEgCzvAKE409/?ref=app

Answer 1

You forgot the &n in scanf, since scanf takes a pointer.

Answer 2

issue is with scanf...change both as below and it is done:
scanf("%d",&n);
for(i=0;i<n;i++)
scanf("%d",&(p[i]));

Answer 3

Thanks to you both , I just forgot & with n..
Thanks .