拓扑排序找环，再统计环上最小值，贡献给 $ans$。

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N=2e5+10;
int n,x[N],rd[N];ll c[N];
bool vis[N];queue<int>q;
void ts()
{
	for(int i=1;i<=n;i++)
		if(rd[i]==0)q.push(i);
	while(!q.empty())
	{
		int u=q.front();q.pop();
		vis[u]=1;int v=x[u];rd[v]--;
		if(rd[v]==0)q.push(v);
	}
}
ll calc(int u)
{
	ll res=c[u];
	while(!vis[u])
	{
		res=min(res,c[u]);
		vis[u]=1;u=x[u];
	}
	return res;
}
void work()
{
	ll ans=0;
	for(int i=1;i<=n;i++)
		if(!vis[i])ans+=calc(i);
	printf("%lld\n",ans);
}
signed main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
		scanf("%d",&x[i]),rd[x[i]]++;
	for(int i=1;i<=n;i++)scanf("%lld",&c[i]);
	ts();work();return 0;
}