Compilare: user.cpp:83:2: warning: no newline at end of file user.cpp: In constructor 'Trie::Trie()': user.cpp:12: warning: unused variable 'i' user.cpp: In function 'void insert(Trie*, char*)': user.cpp:20: warning: NULL used in arithmetic user.cpp: In function 'int del(Trie*, char*)': user.cpp:35: warning: NULL used in arithmetic user.cpp: In function 'int count(Trie*, char*)': user.cpp:55: warning: NULL used in arithmetic user.cpp: In function 'int prefix(Trie*, char*, int)': user.cpp:61: warning: NULL used in arithmetic user.cpp: In function 'int count(Trie*, char*)': user.cpp:57: warning: control reaches end of non-void function