Compilare: main.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] #import<fstream> ^~~~~~ main.cpp:2:14: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] int i,d;main(){std::ifstream("submultimi.in")>>i;std::ofstream g("submultimi.out");for(i=1<<i;--i;g<<'\n')for(;i>>d;i>>d++&1,g<<d<<' ');} ^ main.cpp: In function 'int main()': main.cpp:2:123: warning: value computed is not used [-Wunused-value] int i,d;main(){std::ifstream("submultimi.in")>>i;std::ofstream g("submultimi.out");for(i=1<<i;--i;g<<'\n')for(;i>>d;i>>d++&1,g<<d<<' ');} ~~~~~~^~