Compilare: main.cpp: In function 'int main()': main.cpp:61:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); ++i) ~~^~~~~~~~~~~~ main.cpp: In function 'void BUNA(const string&)': main.cpp:21:62: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen((task + ".out").c_str(), "w", stdout); ^ main.cpp:21:62: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]