Compilare: main.cpp: In function 'int main()': main.cpp:66:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ret.size(); i++) cout << ret[i] << endl; ~~^~~~~~~~~~~~ main.cpp:51:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ghiozdan.in", "r", stdin); ^ main.cpp:52:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ghiozdan.out", "w", stdout); ^