Compilare: user.cpp: In member function ‘void trie::update()’: user.cpp:32:14: warning: unused variable ‘up’ [-Wunused-variable] bool up; ^ user.cpp: In function ‘void change(int, int, trie*, int)’: user.cpp:66:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz==s.size()) ^ user.cpp: In function ‘void write()’: user.cpp:98:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<s.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:131:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<s.size();j++) ^ user.cpp:155:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<s.size();j++) ^ user.cpp:167:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<s.size();j++) ^