Submission #1181498

#	Time	Username	Problem	Language	Result	Execution time	Memory
1181498		meicris	Fountain (eJOI20_fountain)	C++17	0 / 100	83 ms	16964 KiB

fountain

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 100005;
const int LOG = 20;

int N, Q;
vector<int> D, C, next_bigger;
int jump[MAXN][LOG];
int sum[MAXN][LOG];

void preprocess_next_bigger() {
    next_bigger.assign(N, -1);
    stack<int> s;
    for (int i = N - 1; i >= 0; --i) {
        while (!s.empty() && D[i] >= D[s.top()]) {
            s.pop();
        }
        if (!s.empty()) {
            next_bigger[i] = s.top();
        }
        s.push(i);
    }
}

void build_binary_lifting() {
    for (int i = 0; i < N; ++i) {
        jump[i][0] = next_bigger[i];
        sum[i][0] = C[i];
    }

    for (int k = 1; k < LOG; ++k) {
        for (int i = 0; i < N; ++i) {
            int nxt = jump[i][k - 1];
            if (nxt == -1) {
                jump[i][k] = -1;
                sum[i][k] = sum[i][k - 1];
            } else {
                jump[i][k] = jump[nxt][k - 1];
                sum[i][k] = sum[i][k - 1] + sum[nxt][k - 1];
            }
        }
    }
}

int pour(int idx, int V) {
    if (V <= C[idx]) return idx + 1;

    V -= C[idx];

    for (int k = LOG - 1; k >= 0; --k) {
        if (jump[idx][k] != -1 && sum[idx][k] < V) {
            V -= sum[idx][k];
            idx = jump[idx][k];
        }
    }

    idx = jump[idx][0];
    if (idx == -1 || V > C[idx]) return 0;
    return idx + 1;
}

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

    cin >> N >> Q;
    D.resize(N);
    C.resize(N);
    for (int i = 0; i < N; ++i) {
        cin >> D[i] >> C[i];
    }

    preprocess_next_bigger();
    build_binary_lifting();

    while (Q--) {
        int R, V;
        cin >> R >> V;
        cout << pour(R - 1, V) << '\n';
    }

    return 0;
}

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