D - Prevented to Carry Snowman

#include <bits/stdc++.h>

#define rep(i,n) for(int i = 0; i < n; i++) //[0,n)

#define srep(i,a,b) for(int i = a; i < b; i++) //[a,b)

#define all(A) (A).begin(),(A).end()

#define rall(A) (A).rbegin(),(A).rend()

#define pmt(A) next_permutation(A)

using namespace std;

using ll = long long;

using ull = unsigned long long;

using P = pair<ll,ll>;

using pq = priority_queue<ll,vector<ll>,greater<ll>>;

using ppq = priority_queue<P,vector<P>,greater<P>>;

const ll inf = 8e18;

const int iinf = (int)1e9;

const int mod9 = 998244353;

const int mod1 = 1000000007;

struct Edge { int to; ll cost; int from; };

bool compe(const Edge &e,const Edge &e2){ return e.cost < e2.cost; }

using Graph = vector<vector<int>>;

using EGraph = vector<Edge>;

using SGraph = vector<set<ll>>;

template <typename T>

int siz(T& a){ return (int)a.size(); }

ll squa(int a){ return a*a; }

ll ceil(ll a,ll b){ return (a+b-1)/b; }

using namespace std;

​

int res = 0;

void dfs(const Graph &G,const vector<int> &C,int v,int pre,int d,int u){

    res = max(res,d);

​

    for(auto nv : G[v]){

        //cout << v << " " << nv << endl;

        if(nv == pre || C[nv] < u) continue;

        dfs(G,C,nv,v,d+1,u);

    }

}

​

int main(){

    int K; cin >> K;

    vector<int> U(K); rep(i,K) cin >> U[i];

​

    int N; cin >> N;

    Graph G(N);

    rep(i,N-1){

        int A; cin >> A;

        A--;

        G[A].push_back(i+1);

    }

​

    vector<int> C(N);

    srep(i,1,N) cin >> C[i];

​

    rep(i,K){

        dfs(G,C,0,-1,0,U[i]);

        cout << res << endl;

        res = 0;

    }

}

​