Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:29:16: error: variable ‘std::ifstream in’ has initializer but incomplete type ifstream in("z.in"); ^ user.cpp:30:16: error: variable ‘std::ofstream ou’ has initializer but incomplete type ofstream ou("z.out"); ^ user.cpp:32:9: error: ‘n’ was not declared in this scope in>>n>>k; ^ user.cpp:32:12: error: ‘k’ was not declared in this scope in>>n>>k; ^ user.cpp:36:13: error: ‘x’ was not declared in this scope in>>x>>y; ^ user.cpp:36:16: error: ‘y’ was not declared in this scope in>>x>>y; ^ user.cpp: In function ‘int f(int, int, int)’: user.cpp:20:1: warning: control reaches end of non-void function [-Wreturn-type] } ^