Compilare: main.cpp:1:2: warning: #import is a deprecated GCC extension [-Wdeprecated] #import<fstream> ^~~~~~ main.cpp:2:104: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] int g(int a,int b){return b?g(b,a%b):a;}std::ifstream q{"perm2.in"};int v[100005],n,i=1,m,o,p,s=1;main(){q>>n;while(i<=n)q>>v[i++];for(i=1;i<=n;++i)if(v[i]){p=i,m=0;while(v[p])++m,o=v[p],v[p]=0,p=o;s*=m/g(s,m);}std::ofstream{"perm2.out"}<<s;} ^