Compilare: user.cpp: In constructor ‘node::node(int, long long int, node*, node*)’: user.cpp:15: warning: ‘node::val’ will be initialized after user.cpp:13: warning: ‘node* node::left’ user.cpp:17: warning: when initialized here user.cpp: In function ‘int main()’: user.cpp:77: warning: suggest parentheses around ‘&&’ within ‘||’ user.cpp:84: warning: unused variable ‘root’ user.cpp:62: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:63: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:74: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/ccNCP8PJ.o: In function `main': user.cpp:(.text+0x66c): warning: the `gets' function is dangerous and should not be used.