Compilare: user.cpp: In function ‘int getAns(std::string&)’: user.cpp:20:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); i += 2) { ^ user.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + 1 < v.size()) { ^ user.cpp: In function ‘int main()’: user.cpp:52:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("password.in", "r", stdin); ^ user.cpp:53:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("password.out", "w", stdout); ^