Compilare: user.cpp: In function ‘std::tuple<std::vector<int, std::allocator<int> >, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >, int> Read(const char*)’: user.cpp:28:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < line.size(); j++) ^ user.cpp:17:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(file, "r", stdin); ^ user.cpp: In function ‘void Write(const char*, const T&) [with T = std::vector<long long int>; type = long long int]’: user.cpp:159:5: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(file, "w", stdout); ^