Compilare: user.cpp: In member function ‘void aho_corasick_automaton::add_word(const string&, int)’: user.cpp:57:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); ++i) ^ user.cpp: In member function ‘void aho_corasick_automaton::build_fails()’: user.cpp:88:69: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(k && !states[k].transitions[states[nod].letter]) ^ user.cpp:91:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(states[k].transitions[states[nod].letter]) ^ user.cpp:92:63: warning: array subscript has type ‘char’ [-Wchar-subscripts] k=states[k].transitions[states[nod].letter]; ^ user.cpp: In member function ‘void aho_corasick_automaton::fin()’: user.cpp:112:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<states.size(); ++i) ^ user.cpp: In member function ‘int aho_corasick_automaton::run_automaton(const string&)’: user.cpp:137:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); ++i) ^ user.cpp:135:20: warning: unused variable ‘aux’ [-Wunused-variable] int nod=0, aux; ^ user.cpp:147:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:173:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < automaton.states.size (); ++i) ^ user.cpp:174:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < automaton.states[i].word.size (); ++j) ^ user.cpp:156:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("virus.in", "r", stdin); ^ user.cpp:157:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("virus.out", "w", stdout); ^