/in/p2.cpp: In function 'bool tree_hasMonotonicPath_helper(tree_t, int, bool, bool)':
/in/p2.cpp:243:13: error: 'leaf' was not declared in this scope
     else if(leaf(tree)){
             ^~~~
/in/p2.cpp:243:13: note: suggested alternative: 'feof'
     else if(leaf(tree)){
             ^~~~
             feof