/in/main.c: In function 'main':
/in/main.c:21:16: error: 'o' undeclared (first use in this function)
     for (int i=o;i<16;i++){
                ^
/in/main.c:21:16: note: each undeclared identifier is reported only once for each function it appears in
/in/main.c:27:23: error: expected expression before '[' token
         node[i].right=[i*2+1];
                       ^
/in/main.c:29:5: error: implicit declaration of function 'transverse' [-Werror=implicit-function-declaration]
     transverse(node+1,k);
     ^~~~~~~~~~
/in/main.c: At top level:
/in/main.c:33:6: error: conflicting types for 'transverse' [-Werror]
 void transverse(node_t *root, int k){
      ^~~~~~~~~~
/in/main.c:29:5: note: previous implicit declaration of 'transverse' was here
     transverse(node+1,k);
     ^~~~~~~~~~
cc1: all warnings being treated as errors