Compilare: user.cpp: In function ‘void adauga(Trie*, char*)’: user.cpp:27:15: warning: NULL used in arithmetic [-Wpointer-arith] if( *s == NULL ) ^ user.cpp: In function ‘void sterge(Trie*, char*)’: user.cpp:45:15: warning: NULL used in arithmetic [-Wpointer-arith] if( *s == NULL ) ^ user.cpp: In function ‘int aparitie(Trie*, char*)’: user.cpp:72:15: warning: NULL used in arithmetic [-Wpointer-arith] if( *s == NULL ) ^ user.cpp: In function ‘int prefix(Trie*, char*)’: user.cpp:85:15: warning: NULL used in arithmetic [-Wpointer-arith] if( *s == NULL || T -> urm[ *s - 'a' ] == 0 ) ^ user.cpp: In function ‘int aparitie(Trie*, char*)’: user.cpp:81:1: warning: control reaches end of non-void function [-Wreturn-type] } ^