제출 #646583

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
646583		Vanilla	Arboras (RMI20_arboras)	C++17	11 / 100	62 ms	2924 KiB

arboras

#include <bits/stdc++.h>
using namespace std;
typedef long long int64;
const int64 mod = 1e9 + 7;
const int maxn = 1e3 + 2;
int64 dp[maxn], down[maxn], c[maxn][maxn];
int p[maxn];
vector <int> ad [maxn];
int n;

void upd (int u) {
    vector <int64> d;
    for (int v: ad[u]) {
        down[u] = max(down[u], down[v] + c[u][v]);
        d.push_back(down[v] + c[u][v]);
    }
    sort(d.rbegin(), d.rend());
    for (int i = 0; i < min((int) d.size(), 2); i++) dp[u]+=d[i];
}

void dfs (int u) {
    for (int v: ad[u]) {
        dfs(v);
    }
    upd(u);
}

int64 calc () {
    for (int i = 0; i < n; i++) dp[i] = 0;
    dfs(0);
    int64 rs = 0;
    for (int i = 0; i < n; i++){
        rs+=dp[i];
    }
    return rs % mod;
}

int main() {
    cin >> n;
    for (int i = 1; i <= n - 1; i++){
        int x;
        cin >> x;
        ad[x].push_back(i);
        p[i] = x;
    }
    for (int i = 1; i <= n - 1; i++){
        int x;
        cin >> x;
        c[p[i]][i] = x;
    }
    cout << calc() << "\n";
    int q;
    cin >> q;
    while (q--) {
        int64 x,y;
        cin >> x >> y;
        c[p[x]][x] += y;
        cout << calc() << "\n";
    }
    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 13
• Subtask 3: 0 / 31
• Subtask 4: 0 / 45