Submission #853456

#	Time	Username	Problem	Language	Result	Execution time	Memory
853456		heartbeat	Fountain (eJOI20_fountain)	C++17	0 / 100	115 ms	524288 KiB

fountain

#include <bits/stdc++.h>
using namespace std;
#define ll long long
struct Tree {
    int sz = 21;
    vector<vector<int>> table;
    vector<vector<ll>> sum;
    Tree (){}
    Tree (int n) {
        // while ((1 << sz) <= n) sz++;
        table = vector<vector<int>> (sz, vector<int> ((1 << sz)));
        sum = vector<vector<ll>> (sz, vector<ll> ((1 << sz)));
    }
    void add_cost(int u, int x) {
        sum[0][u] = x;
    }
    void add_edge(int u, int v) {
        table[0][u] = v;
    }
    void build() {
        for (int bit = 1; bit < sz; ++bit) {
            for (int Node = 1; Node < sz; ++Node) {
                int to = table[bit - 1][Node];
                table[bit][Node] = table[bit - 1][to];
                sum[bit][Node] = sum[bit - 1][Node] + sum[bit - 1][to];
            }
        }
    }
};
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, q, idx = 1;
    cin >> n >> q;
    Tree tree(n);
    vector<pair<int, int>> v(n);
    for (auto &[a, b] : v) {
        cin >> a >> b;
        tree.add_cost(idx++, b);
    }
    vector<int> track;
    for (int i = n - 1; i >= 0; --i) {
        while (track.size() && v[track.back()].first <= v[i].first) {
            track.pop_back();
        }
        if (track.size()) {
            tree.add_edge(i + 1, track.back() + 1);
        }
        track.push_back(i);
    }
    tree.build();
    for (int i = 0, Node, x; i < q; ++i) {
        cin >> Node >> x;
        for (int bit = tree.sz - 1; bit >= 0 && Node; --bit) {
            // cout << bit << " " << Node << " " << tree.sum[bit][Node] << " " << x << endl;
            if (tree.sum[bit][Node] < x) {
                x -= tree.sum[bit][Node];
                Node = tree.table[bit][Node];
            }
        }
        cout << Node << '\n';
    }
    return 0;
}
/*
6 5
4 10
6 8
3 5
4 14
10 9
4 20
1 25
6 30
5 8
3 13
2 8
*/

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40