Compilare: user.cpp: In function ‘void add(trie*, int)’: user.cpp:28:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == fo.size()) ^ user.cpp: In function ‘void query(trie*, int)’: user.cpp:46:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0 ; j < (t -> terminal).size() ; ++j) ^ user.cpp:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == p.size()) return; ^