View Compilation Error

0_0_37652390_18361.cpp: In function 'void build(int, int, int)':
0_0_37652390_18361.cpp:161:13: error: invalid initialization of reference of type 'Node&' from expression of type 'int'
     pushup(o);
             ^
0_0_37652390_18361.cpp:56:6: note: in passing argument 1 of 'void pushup(Node&, Node&, Node&)'
 void pushup(Node &u,Node &l,Node &r){
      ^
0_0_37652390_18361.cpp: In function 'void update(int, int, int)':
0_0_37652390_18361.cpp:204:13: error: invalid initialization of reference of type 'Node&' from expression of type 'int'
     pushup(o);
             ^
0_0_37652390_18361.cpp:56:6: note: in passing argument 1 of 'void pushup(Node&, Node&, Node&)'
 void pushup(Node &u,Node &l,Node &r){
      ^