Compilare: user.cpp: In function ‘void query0()’: user.cpp:23:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2;i<s.size();i++) ^ user.cpp: In function ‘int query1(trie*, int)’: user.cpp:38:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos==s.size()) ^ user.cpp: In function ‘int query2()’: user.cpp:55:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2;i<s.size();i++) ^ user.cpp: In function ‘int query3()’: user.cpp:67:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=2;i<s.size();i++) ^