Eroare de compilare: user.cpp: In function ‘int pow2(int, int)’: user.cpp:28:7: warning: variable ‘is_negative’ set but not used [-Wunused-but-set-variable] bool is_negative = false; ^ user.cpp: In function ‘int main(int, char**)’: user.cpp:52:16: error: variable ‘std::ifstream input’ has initializer but incomplete type ifstream input("lgput.in"); ^ user.cpp:53:17: error: variable ‘std::ofstream output’ has initializer but incomplete type ofstream output("lgput.out"); ^