Submission #772484

#	Time	Username	Problem	Language	Result	Execution time	Memory
772484		BlockOG	Fountain (eJOI20_fountain)	C++14	100 / 100	451 ms	19240 KiB

fountain

#include <iostream>
#include <vector>
#include <utility>
#include <climits>

using namespace std;

/*
6 5
4 10
6 8
3 5
4 14
10 9
4 20
1 25
6 30
5 8
3 13
2 8

*/

int main() {
    int n, q; cin >> n >> q;

    int diameters[n];
    int next[n][20];
    int sum[n][20];
    for (int i = 0; i < n; i++) cin >> diameters[i] >> sum[i][0];

    vector<pair<int, int>> st = { { INT_MAX, -1 } };
    for (int i = n - 1; i >= 0; i--) {
        while (st.back().first <= diameters[i]) st.pop_back();
        next[i][0] = st.back().second;
        st.push_back({ diameters[i], i });
    }

    for (int j = 1; j < 20; j++) {
        for (int i = 0; i < n; i++) {
            if (next[i][j - 1] == -1) {
                next[i][j] = -1;
                sum[i][j] = sum[i][j - 1];
                continue;
            }
            next[i][j] = next[next[i][j - 1]][j - 1];
            sum[i][j] = sum[i][j - 1] + sum[next[i][j - 1]][j - 1];
        }
    }

    for (int it = 0; it < q; it++) {
        int r, v; cin >> r >> v; r--;

        for (int i = 19; i >= 0; i--) {
            if (sum[r][i] >= v) continue;
            v -= sum[r][i];
            r = next[r][i];
            if (r == -1) break;
        }

        cout << r + 1 << endl;
    }
}

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