10pts
https://www.luogu.com.cn/record/30924231
不是妹子,刚学OI

#include<bits/stdc++.h>


using namespace std;


struct Node {
    char ch;
    int parent;
    vector<int> sub;
};


Node tree[500010];
long long dp[500010];
stack<int> last;
long long ans;


void dfs(int node);


int main(void) {
    int n;
    scanf("%d", &n);
    string s;
    cin >> s;
    for (register int i = 1; i <= n; ++i) {
        tree[i].ch = s[i - 1];
        tree[i].parent = 0;
        tree[i].sub.clear();
    }
    for (register int i = 2; i <= n; ++i) {
        scanf("%d", &(tree[i].parent));
        tree[tree[i].parent].sub.push_back(i);
    }
    dfs(1);
    for (register int i = 1; i <= n; ++i) {
        ans ^= (long long)(i) * dp[i];
    }
    printf("%lld\n", ans);
    return 0;
}


void dfs(int node) {
    if (tree[node].ch == '(') {
        dp[node] = dp[tree[node].parent];
        last.push(node);
        for (register int i = 0; i < tree[node].sub.size(); ++i) {
            dfs(tree[node].sub[i]);
        }
        last.pop();
    }
    else {
        if (last.empty()) {
            dp[node] = dp[tree[node].parent];
            for (register int i = 0; i < tree[node].sub.size(); ++i) {
                dfs(tree[node].sub[i]);
            }
        }
        else {
            if (last.top() == 1 || tree[tree[last.top()].parent].ch == '(') {
                dp[node] = dp[tree[node].parent] + 1;
                int tmp = last.top();
                last.pop();
                for (register int i = 0; i < tree[node].sub.size(); ++i) {
                    dfs(tree[node].sub[i]);
                }
                last.push(tmp);
            }
            else {
                dp[node] = dp[tree[node].parent] + dp[tree[last.top()].parent] + 1;
                int tmp = last.top();
                last.pop();
                for (register int i = 0; i < tree[node].sub.size(); ++i) {
                    dfs(tree[node].sub[i]);
                }
                last.push(tmp);
            }
        }
    }
    return;
}