Compilare: user.cpp: In constructor ‘Trie::Trie()’: user.cpp:20:42: warning: passing NULL to non-pointer argument 2 of ‘void* memset(void*, int, size_t)’ [-Wconversion-null] memset(son, NULL, sizeof(son)); ^ user.cpp: In function ‘void Ins(Trie*, char*)’: user.cpp:29:15: warning: NULL used in arithmetic [-Wpointer-arith] if (*s == NULL) ^ user.cpp: In function ‘bool Del(Trie*, char*)’: user.cpp:46:15: warning: NULL used in arithmetic [-Wpointer-arith] if (*s == NULL) ^ user.cpp: In function ‘int Nr_Aparitii(Trie*, char*)’: user.cpp:66:15: warning: NULL used in arithmetic [-Wpointer-arith] if (*s == NULL) ^ user.cpp: In function ‘int Max_Prefix(Trie*, char*, int)’: user.cpp:80:15: warning: NULL used in arithmetic [-Wpointer-arith] if (*s == NULL || nod->son[*s - 'a'] == NULL) ^