/in/foo.cc: In member function 'void SegTree::build(node*&, int, int)':
/in/foo.cc:30:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         }int mid=l+r>>1;
                  ~^~
/in/foo.cc: In member function 'void SegTree::add(node*, int, int)':
/in/foo.cc:40:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid=l+r>>1;
                 ~^~