Eroare de compilare: user.cpp: In function ‘bool iscump(long long int)’: user.cpp:8:9: warning: unused variable ‘k’ [-Wunused-variable] int k=a/2; ^ user.cpp: In function ‘int main()’: user.cpp:28:15: error: variable ‘std::ifstream f’ has initializer but incomplete type ifstream f("cumpanit.in"); ^ user.cpp:29:15: error: variable ‘std::ofstream g’ has initializer but incomplete type ofstream g("cumpanit.out"); ^