C++ 代码

#include <iostream>
#include <cstring>

using namespace std;

const int N=500010;
long long f[N],k[N],t[N],l[N];
long long n,ans;
string s;

int main()
{
    cin>>n;
    cin>>s;
    s=' '+s;
    for(int i=2;i<=n;i++)
    cin>>f[i];

    k[1]=0;
    t[1]=0;
    f[1]=0;

    for(int i=2;i<=n;i++)
    {
        if(s[i]=='(') {k[i]=k[f[i]];continue;}
        int j=i,x=1;
        while(j>0)
        {
            j=f[j];
            if(s[j]=='(') x--;else x++;
            if(x==0) {t[i]=t[f[j]]+1;break;}
        }
        k[i]=k[f[i]]+t[i];
    }

    for(int i=2;i<=n;i++)
    ans=ans^(i*k[i]);

    cout<<ans;

    return 0;
}