Submission #895807

#	Time	Username	Problem	Language	Result	Execution time	Memory
895807		tvladm2009	Fountain (eJOI20_fountain)	C++17	100 / 100	308 ms	40744 KiB

fountain

#include <bits/stdc++.h>
#define int ll

using namespace std;

typedef long long ll;
const int LOG = 20;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    vector<int> d(n + 2), c(n + 2);
    for (int i = 1; i <= n; ++i) cin >> d[i] >> c[i];
    vector<int> l(n + 1), stk;
    for (int i = n; i >= 1; --i) {
        while (!stk.empty() && d[i] >= d[stk.back()]) {
            stk.pop_back();
        }
        if (stk.empty()) {
            l[i] = 0;
        } else {
            l[i] = stk.back();
        }
        stk.push_back(i);
    }
    vector<vector<int>> anc(LOG, vector<int>(n + 1));
    vector<vector<int>> sum(LOG, vector<int>(n + 1, 0LL));
    for (int i = 1; i <= n; ++i) {
        anc[0][i] = l[i];
        sum[0][i] = c[l[i]];
    }
    for (int h = 1; h < LOG; ++h) {
        for (int i = 1; i <= n; ++i) {
            anc[h][i] = anc[h - 1][anc[h - 1][i]];
            sum[h][i] = sum[h - 1][i] + sum[h - 1][anc[h - 1][i]];
        }
    }
    while (q--) {
        int r, cap;
        cin >> r >> cap;
        if (c[r] >= cap) {
            cout << r << "\n";
            continue;
        }
        cap -= c[r];
        ll cur = 0;
        for (int k = LOG - 1; k >= 0; --k) {
            if (anc[k][r] != 0 && cur + sum[k][r] < cap) {
                cur += sum[k][r];
                r = anc[k][r];
            }
        }
        if (l[r] == n + 1) {
            cout << "0\n";
            continue;
        }
        cout << l[r] << "\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: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40