/in/foo.cc: In function 'int ans(int*, int*, int)':
/in/foo.cc:17:9: error: two consecutive '[' shall only introduce an attribute before '[' token
   s+=f(a[[h1],b[r2]);
         ^
/in/foo.cc:20:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^