View Compilation Error

0_0_37321947_19055.cpp:31:17: error: no matching function for call to 'Node::Node()'
 } node[maxn << 2];
                 ^
0_0_37321947_19055.cpp:31:17: note: candidates are:
0_0_37321947_19055.cpp:26:2: note: Node::Node(int, int)
  Node(int _l, int _r) : l(_l), r(_r)
  ^
0_0_37321947_19055.cpp:26:2: note:   candidate expects 2 arguments, 0 provided
0_0_37321947_19055.cpp:19:8: note: constexpr Node::Node(const Node&)
 struct Node
        ^
0_0_37321947_19055.cpp:19:8: note:   candidate expects 1 argument, 0 provided
0_0_37321947_19055.cpp:19:8: note: constexpr Node::Node(Node&&)
0_0_37321947_19055.cpp:19:8: note:   candidate expects 1 argument, 0 provided