Compilare: user.cpp: In member function ‘void aho_corasick_automaton::add_word(const string&, int)’: user.cpp:62:31: 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:93:69: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(k && !states[k].transitions[states[nod].letter]) ^ user.cpp:96:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(states[k].transitions[states[nod].letter]) ^ user.cpp:97:63: 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:117:36: 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:142:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); ++i) ^ user.cpp:140:20: warning: unused variable ‘aux’ [-Wunused-variable] int nod=0, aux; ^ user.cpp:152:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:178:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<automaton.states.size(); ++i) ^ user.cpp:180:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<automaton.states[i].word.size(); ++j) ^ user.cpp:159:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.in", "r", stdin); ^ user.cpp:160:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasick.out", "w", stdout); ^ user.cpp:164:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^