Compilare: main.cpp: In function 'void setupIO(const string&)': main.cpp:50:56: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen((PROB + ".in").c_str(), "r", stdin); ^ main.cpp:51:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen((PROB + ".out").c_str(), "w", stdout); ^