Compilare: main.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] 1 | #import<fstream> | ^~~~~~ main.cpp:2:11: warning: multi-character character constant [-Wmultichar] 2 | int64_t s['썐'],n,i=2,j,r;main(){std::ifstream{"fractii.in"}>>n;for(;i<=n;s[i++]=i-1);for(i=2;i<=n;++i)for(j=i+i,r+=s[i];j<=n;j+=i)s[j]-=s[i];std::ofstream{"fractii.out"}<<r*2+1;} | ^~~~ main.cpp:2:28: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] 2 | int64_t s['썐'],n,i=2,j,r;main(){std::ifstream{"fractii.in"}>>n;for(;i<=n;s[i++]=i-1);for(i=2;i<=n;++i)for(j=i+i,r+=s[i];j<=n;j+=i)s[j]-=s[i];std::ofstream{"fractii.out"}<<r*2+1;} | ^~~~ main.cpp: In function 'int main()': main.cpp:2:79: warning: operation on 'i' may be undefined [-Wsequence-point] 2 | int64_t s['썐'],n,i=2,j,r;main(){std::ifstream{"fractii.in"}>>n;for(;i<=n;s[i++]=i-1);for(i=2;i<=n;++i)for(j=i+i,r+=s[i];j<=n;j+=i)s[j]-=s[i];std::ofstream{"fractii.out"}<<r*2+1;} | ~^~ main.cpp:2:79: warning: operation on 'i' may be undefined [-Wsequence-point]