Compilare: main.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] #import <fstream> ^~~~~~ main.cpp:2:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main(){std::fstream c("clasic.in");std::ofstream o("clasic.out");int i,R,x;for(c>>i;i--;o<<R<<"\n",R=0)for(c>>x;c>>x;R^=x);} ^