Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:23:5: error: ‘ifstream’ was not declared in this scope ifstream input_file; ^ user.cpp:23:5: note: suggested alternative: In file included from /usr/include/c++/4.8/ios:38:0, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: /usr/include/c++/4.8/iosfwd:157:34: note: ‘std::ifstream’ typedef basic_ifstream<char> ifstream; ^ user.cpp:23:14: error: expected ‘;’ before ‘input_file’ ifstream input_file; ^ user.cpp:24:5: error: ‘input_file’ was not declared in this scope input_file.open( "z.in" ); ^ user.cpp:31:5: error: ‘ofstream’ was not declared in this scope ofstream output_file; ^ user.cpp:31:5: note: suggested alternative: In file included from /usr/include/c++/4.8/ios:38:0, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: /usr/include/c++/4.8/iosfwd:160:34: note: ‘std::ofstream’ typedef basic_ofstream<char> ofstream; ^ user.cpp:31:14: error: expected ‘;’ before ‘output_file’ ofstream output_file; ^ user.cpp:32:5: error: ‘output_file’ was not declared in this scope output_file.open("z.out"); ^