Submission #957156

#	Time	Username	Problem	Language	Result	Execution time	Memory
957156		thinknoexit	Fireworks (APIO16_fireworks)	C++17	7 / 100	14 ms	33464 KiB

fireworks

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 300300;
bool leaf[N];
vector<pair<int, int>> adj[N];
ll ansl[N], ansr[N], ans[N];
priority_queue<ll> l[N];
priority_queue<ll, vector<ll>, greater<ll>> r[N];
void dfs(int v, ll d) {
    if (leaf[v]) {
        ansl[v] = d;
        ansr[v] = d;
        return;
    }
    for (auto& [x, w] : adj[v]) {
        dfs(x, d + w);
        ans[v] += ans[x];
        if (l[v].empty()) {
            l[v].push(ansl[x]);
            r[v].push(ansr[x]);
            continue;
        }
        ll nowl = l[v].top(), nowr = r[v].top();
        if (ansr[x] < nowl) {
            ans[v] += nowl - ansr[x];
            l[v].push(ansl[x]);
            l[v].push(ansr[x]);
            l[v].pop();
            r[v].push(nowl);
        }
        else if (nowr < ansl[x]) {
            ans[v] += ansl[x] - nowr;
            r[v].push(ansl[x]);
            r[v].push(ansr[x]);
            r[v].pop();
            l[v].push(nowr);
        }
        else {
            l[v].push(ansl[x]);
            r[v].push(ansr[x]);
        }
    }
    ansl[v] = l[v].top();
    ansr[v] = r[v].top();
}
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    for (int i = 2;i <= n + m;i++) {
        int p, c;
        cin >> p >> c;
        adj[p].push_back({ i, c });
        if (i > n) leaf[i] = 1;
    }
    dfs(1, 0);
    cout << ans[1] << '\n';
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45