/in/foo.c: In function 'main':
/in/foo.c:22:9: warning: zero-length gnu_printf format string [-Wformat-zero-length]
  printf("");
         ^~
/in/foo.c:20:10: warning: unused variable 'q' [-Wunused-variable]
  int n,i,q,r[10],x,y,p,z;
          ^
/in/foo.c:39:1: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
 printf("%d",p);
 ^~~~~~~~~~~~~~