今晚ABC DE求调，共悬7关

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int L=60,mod=998244353;
int n,d,ans,a[L+5];
int qpow(int a,int x)
{
	if(x==0)return 1;
	if(x==1)return a%mod;
	int c=qpow(a,x/2),y=qpow(a,x%2);
	return c*y%mod*c%mod;
}
signed main()
{
	cin>>n;
	if(n==0)
	{
		cout<<0;
		return 0;
	}
	d=log10l(n)+1;
	a[0]=n%mod;
	for(int i=1;i<L;i++)a[i]=a[i-1]*(1+qpow(10,(1ll<<(i-1))%(mod-1)*d))%mod;
	for(int i=L-1;i>=0;i--)
	{
		if(n<(1ll<<i))continue;
		ans=((ans*qpow(10,(1ll<<i)%(mod-1)*d))%mod+a[i])%mod;
		n-=(1ll<<i);
	}
	cout<<ans;
}

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=200005;
int n,tp,len,ans,G,fa[N],rt[N],dep[N],vis[N],lz[N];
vector<int> g[N];
stack<int> s,t;
void dfs1(int u,int fa)
{
	if(vis[u])
	{
		if(!G)return;
		len=G=0;
		while(s.top()!=u)
		{
			t.push(s.top());
			s.pop();
			len++;
		}
		t.push(u);
		s.pop();
		len++;
		while(t.size())
		{
			rt[t.top()]=1;
			lz[t.top()]=len;
			t.pop();
		}
		return;
	}
	vis[u]=1;
	s.push(u);
	int f=1;
	for(int v:g[u])
	{
		if(v==fa&&(f||(!G)))
		{
			f=0;
			continue;
		}
		dfs1(v,u);
	}
}
void dfs2(int u,int fa,int l)
{
	if(vis[u])return;
	vis[u]=1;
	lz[u]=l;
	for(int v:g[u])
	{
		if(v==fa)continue;
		dfs2(v,u,l);
	}
}
void dfs3(int u,int fa)
{
	dep[u]=dep[fa]+1;
	for(int v:g[u])
	{
		if(v==fa||rt[v])continue;
		dfs3(v,u);
	}
}
signed main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>fa[i];
		g[fa[i]].push_back(i);
		g[i].push_back(fa[i]);
	}
	for(int i=1;i<=n;i++)if(!vis[i])
	{
		G=1;
		dfs1(i,0);
	}
	memset(vis,0,sizeof(vis));
	for(int i=1;i<=n;i++)if(rt[i]&&!vis[i])dfs2(i,0,lz[i]);
	for(int i=1;i<=n;i++)if(rt[i])dfs3(i,0);
	for(int i=1;i<=n;i++)ans+=dep[i]+lz[i]-1;
	cout<<ans;
}