Compilare: main.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] 1 | #import<fstream> | ^~~~~~ main.cpp:3:50: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] 3 | std::ofstream f{"biti.out"};int l[1<<21],n,i,a,o;main(){std::ifstream{"biti.in"}>>n;for(o=1<<(n-1);!(a&1);l[a]=1,a|=o,o/=2);f<<n+(1<<n)-1<<'\n';F(0,n)f<<0;a=0;o=~(1<<(n-1));F(n,1<<n)f<<(l[a=(a&o)*2]?a|=1,1:0),l[a]=1;F(0,n-1)f<<0;} | ^~~~