Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:8:1: error: ‘string’ was not declared in this scope string s; ^ user.cpp:8:1: note: suggested alternative: In file included from /usr/local/include/c++/4.8.0/iosfwd:39:0, from /usr/local/include/c++/4.8.0/ios:38, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:1: /usr/local/include/c++/4.8.0/bits/stringfwd.h:62:33: note: ‘std::string’ typedef basic_string<char> string; ^ user.cpp:8:8: error: expected ‘;’ before ‘s’ string s; ^ user.cpp:9:1: error: ‘ifstream’ was not declared in this scope ifstream f1 ("pufu.in"); ^ user.cpp:9:1: note: suggested alternative: In file included from /usr/local/include/c++/4.8.0/ios:38:0, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:1: /usr/local/include/c++/4.8.0/iosfwd:157:34: note: ‘std::ifstream’ typedef basic_ifstream<char> ifstream; ^ user.cpp:9:10: error: expected ‘;’ before ‘f1’ ifstream f1 ("pufu.in"); ^ user.cpp:10:1: error: ‘ofstream’ was not declared in this scope ofstream f2 ("pufu.out"); ^ user.cpp:10:1: note: suggested alternative: In file included from /usr/local/include/c++/4.8.0/ios:38:0, from /usr/local/include/c++/4.8.0/ostream:38, from /usr/local/include/c++/4.8.0/iostream:39, from user.cpp:1: /usr/local/include/c++/4.8.0/iosfwd:160:34: note: ‘std::ofstream’ typedef basic_ofstream<char> ofstream; ^ user.cpp:10:10: error: expected ‘;’ before ‘f2’ ofstream f2 ("pufu.out"); ^ user.cpp:11:5: error: ‘f1’ was not declared in this scope if (f1.is_open()) ^ user.cpp:14:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<=t;i++) ^