Submission #1231607

#	Time	Username	Problem	Language	Result	Execution time	Memory
1231607		bangan	Tree (IOI24_tree)	C++20	0 / 100	2097 ms	44176 KiB

tree

#include "tree.h"
#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define ll long long

const int N = 200200;

int n;
std::vector<int> w, p;
vector<int> adj[N];


ll res;
ll sum[N];
vector<int> dfs(int v, ll l, ll r) {
    if (adj[v].empty()) {
        sum[v] = l;
        res += l;
        return {v};
    }

    vector<int> sub{v};
    sum[v]=0;
    for (int u : adj[v]) {
        auto vec = dfs(u, l, r);
        sum[v] += sum[u];
        for (int x : vec) sub.pb(x);
    }

    if (sum[v] <= r) return sub;

    sort(sub.begin(), sub.end(), [&](int i, int j) {
        return w[i] > w[j];
    });

    while (sum[v] != r) {
        int x = sub.back();
        sub.pop_back();
        
        int save_x = x;
        ll mn = sum[v] - r;
        while (x != v) {
            mn = min(mn, sum[x] - l);
            x = p[x];
        }

        x = save_x;
        res += mn * w[x];

        while (x != v) {
            sum[x] -= mn;
            x = p[x];
        }
        assert(v==x);
        sum[x] -= mn;
    }
    return sub;
}

void init(std::vector<int> P, std::vector<int> W) {
    p = P;
    w = W;
    n = W.size();
    for (int i=1; i<n; i++) adj[P[i]].pb(i);
}

long long query(int L, int R) {
    res = 0;
    dfs(0, L, R);
    return res;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 10
• Subtask 2: 0 / 13
• Subtask 3: 0 / 18
• Subtask 4: 0 / 7
• Subtask 5: 0 / 11
• Subtask 6: 0 / 22
• Subtask 7: 0 / 19