foo.cc: In function ‘int main()’:
foo.cc:33:18: warning: unused variable ‘b’ [-Wunused-variable]
   33 |         int a[n],b[n];
      |                  ^
foo.cc: In function ‘int findgy(int*, int)’:
foo.cc:29:1: warning: control reaches end of non-void function [-Wreturn-type]
   29 | }
      | ^