存码

#include<bits/stdc++.h>
using namespace std;
#define LL long long
const int N = 1e5+5,mod = 1e9+7;
int n,a[N];
vector<int> g[N];
LL _2[N],tmp;
void dfs(int u,int m)
{
	for(int v:g[u]) dfs(v,m);
	int cnt=(a[u]>>m)&1,sz=1;
	for(int v:g[u]) cnt+=((a[v]>>m)&1),sz++;
	// printf("%d %d %d\n",u,cnt,sz);
	if(cnt==0||sz==1) return;
	if(u==1)
	{
		if(((a[u]>>m)&1)&&cnt>=2) tmp=(tmp+(_2[cnt-2]*_2[sz-cnt]-1)*_2[n-sz]%mod)%mod;
		else if(!((a[u]>>m)&1)) tmp=(tmp+(_2[cnt-1]*_2[sz-1-cnt])*_2[n-sz]%mod)%mod;
	}
	else
	{
		tmp=(tmp+(_2[cnt-1]*_2[sz-cnt]-cnt)*_2[n-sz-1]%mod)%mod;
	}
}
int main()
{
	freopen("in.in","r",stdin);
	freopen("out.out","w",stdout);
	scanf("%d",&n);
	_2[0]=1; for(int i=1;i<=max(n,30);i++) _2[i]=(_2[i-1]<<1)%mod;
	for(int i=1;i<=n;i++) scanf("%d",&a[i]);
	for(int i=2;i<=n;i++)
	{
		int x; scanf("%d",&x); g[x].push_back(i);
	}
	LL ans=0;
	for(int i=0;i<=30;i++)
	{
		tmp=0;
		// printf("%d:\n",i);
		dfs(1,i);
		ans=(ans+_2[i]*tmp%mod)%mod;
	}
	printf("%lld\n",ans);
	return 0;
}