Compilare: main.cpp:2:92: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] 2 | int n,m,v[250001],i=1,x,y,k;std::ifstream f("stramosi.in");std::ofstream g("stramosi.out");main(){for(f>>n>>m;i<=n;f>>v[i],++i)k+=(v[i]==i-1);if(k==n)while(f>>x>>y)g<<((x>=y)?(x-y):0)<<'\n';else while(f>>x>>y){while(y--&&x)x=v[x];g<<x<<'\n';}} | ^~~~