/in/foo.cc: In function 'void update(int, int, int, int, int, int)':
/in/foo.cc:104:20: warning: unused variable 'tmp' [-Wunused-variable]
  int mid = (l+r)/2,tmp;
                    ^~~
/in/foo.cc: In function 'int qur(int, int, int, int)':
/in/foo.cc:89:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^