Eroare de compilare: In file included from /usr/local/include/c++/4.8.0/ext/hash_set:60:0, from user.cpp:2: /usr/local/include/c++/4.8.0/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header which may be removed without further notice at a future date. Please use a non-deprecated interface with equivalent functionality instead. For a listing of replacement headers and interfaces, consult the file backward_warning.h. To disable this warning use -Wno-deprecated. [-Wcpp] #warning \ ^ user.cpp: In function ‘int main()’: user.cpp:9:5: error: ‘f’ was not declared in this scope f>>n; ^