Eroare de compilare: user.cpp:9:11: error: variable ‘std::ifstream f’ has initializer but incomplete type ifstream f("apm.in"); ^ user.cpp:10:11: error: variable ‘std::ofstream g’ has initializer but incomplete type ofstream g("apm.out"); ^ user.cpp: In function ‘int main()’: user.cpp:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); ++i) ^