Compilare: user.cpp: In constructor ‘node::node(int, long long int, node*, node*)’: user.cpp:16: warning: ‘node::val’ will be initialized after user.cpp:14: warning: ‘node* node::left’ user.cpp:18: warning: when initialized here user.cpp: In function ‘int main()’: user.cpp:100: warning: unused variable ‘root’ user.cpp:76: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:77: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:80: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result