/in/foo.cc: In function 'int cq(int)':
/in/foo.cc:8:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k,t=0;
        ^
/in/foo.cc:8:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,t=0;
          ^
/in/foo.cc:15:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int sub(int)':
/in/foo.cc:26:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:34:14: warning: array subscript is above array bounds [-Warray-bounds]
         a[501]=0;
         ~~~~~^