Submission #463366

#	Time	Username	Problem	Language	Result	Execution time	Memory
463366		tengiz05	Fountain (eJOI20_fountain)	C++17	100 / 100	500 ms	27428 KiB

fountain

#include <bits/stdc++.h>

using i64 = long long;

struct SegmentTree {
    int n;
    std::vector<int> t;
    SegmentTree(int n, int Fill) : n(n), t(2 * n, Fill) {}
    void modify(int p, int val) {
        for (t[p += n] = val; p > 1; p >>= 1) {
            t[p >> 1] = std::min(t[p], t[p ^ 1]);
        }
    }
    int rangeMin(int l, int r) {
        int res = n;
        for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
            if (l % 2 == 1) {
                res = std::min(res, t[l++]);
            }
            if (r % 2 == 1) {
                res = std::min(res, t[--r]);
            }
        }
        return res;
    }
};

constexpr int Log = 20;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n, q;
    std::cin >> n >> q;
    
    std::vector<int> d(n), c(n);
    for (int i = 0; i < n; i++) {
        std::cin >> d[i] >> c[i];
    }
    
    std::vector<int> pr(n + 2);
    for (int i = 0; i < n; i++) {
        pr[i + 1] = pr[i] + c[i];
    }
    pr[n + 1] = pr[n];
    
    auto X = d;
    std::sort(X.begin(), X.end());
    X.erase(std::unique(X.begin(), X.end()), X.end());
    for (auto &x : d) {
        x = std::lower_bound(X.begin(), X.end(), x) - X.begin();
    }
    
    std::vector go(Log, std::vector<int>(n + 1, n));
    std::vector need(Log, std::vector<i64>(n + 1, 1e9));
    
    SegmentTree seg(n + 1, n);
    
    for (int i = n - 1; i >= 0; i--) {
        go[0][i] = seg.rangeMin(d[i] + 1, n + 1);
        need[0][i] = c[i];
        for (int j = 1; j < Log; j++) {
            go[j][i] = go[j - 1][go[j - 1][i]];
            need[j][i] = need[j - 1][i] + need[j - 1][go[j - 1][i]];
        }
        seg.modify(d[i], i);
    }
    
    while (q--) {
        int u, v;
        std::cin >> u >> v;
        u--;
        for (int i = Log - 1; i >= 0; i--) {
            if (need[i][u] < v) {
                v -= need[i][u];
                u = go[i][u];
                // std::cout << i << " " << u << " " << v << "\n";
            }
        }
        if (u == n) {
            std::cout << 0 << "\n";
        } else {
            std::cout << u + 1 << "\n";
        }
    }
    
    return 0;
}

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