Submission #772761

#	Time	Username	Problem	Language	Result	Execution time	Memory
772761		BlockOG	Fountain (eJOI20_fountain)	C++14	100 / 100	432 ms	18264 KiB

fountain

#include <iostream>

using namespace std;

int diameters[100000];
int down[100000][20];
int sum[100000][20];

int st[100001][2];
int sp = 1;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    st[0][0] = 1000000001;
    st[0][1] = -1;

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

    for (int i = n - 1; i >= 0; i--) {
        while (st[sp - 1][0] <= diameters[i]) sp--;
        down[i][0] = st[sp - 1][1];
        st[sp][0] = diameters[i];
        st[sp++][1] = i;
    }

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

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

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