Submission #894864

#	Time	Username	Problem	Language	Result	Execution time	Memory
894864		juliany2	Railway Trip 2 (JOI22_ho_t4)	C++17	35 / 100	2061 ms	24248 KiB

Main

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) (x).begin(), (x).end()

template<class T> struct ST {
    static constexpr T ID = {(int) -1e9, 0}; // or whatever ID
    inline T comb(T a, T b) { return max(a, b); } // or whatever function

    int sz;
    vector<T> t;

    void init(int _sz, T val = ID) {
        t.assign((sz = _sz) * 2, ID);
    }
    void init(vector<T> &v) {
        t.resize((sz = v.size()) * 2);
        for (int i = 0; i < sz; ++i)
            t[i + sz] = v[i];
        for (int i = sz - 1; i; --i)
            t[i] = comb(t[i * 2], t[(i * 2) | 1]);
    }
    void upd(int i, T x) {
        for (t[i += sz] = x; i > 1; i >>= 1)
            t[i >> 1] = comb(t[i], t[i ^ 1]);
    }
    T query(int l, int r) {
        T ql = ID, qr = ID;
        for (l += sz, r += sz + 1; l < r; l >>= 1, r >>= 1) {
            if (l & 1) ql = comb(ql, t[l++]);
            if (r & 1) qr = comb(t[--r], qr);
        }
        return comb(ql, qr);
    }
};

const int N = 1e5 + 7, L = 20;
int n, k, m;
int r[N], lift[N][L];
vector<int> e[N];

int main() {
    cin.tie(0)->sync_with_stdio(false);

    cin >> n >> k >> m;

    for (int i = 1; i <= m; i++) {
        int a, b;
        cin >> a >> b;

        int s = min(b, a + k - 1);
        e[a].push_back(b);
        e[s + 1].push_back(-b);
    }

    ST<array<int, 2>> st;
    st.init(n + 1);

    multiset<int> s;
    for (int i = 1; i <= n; i++) {
        for (int x : e[i]) {
            if (x > 0)
                s.insert(x);
            else
                s.erase(s.find(-x));
        }

        if (s.size())
            r[i] = *s.rbegin();

        st.upd(i, {r[i], i});
    }

    for (int i = n; i >= 1; i--) {
        if (r[i])
            lift[i][0] = st.query(i, r[i])[1];
        else
            lift[i][0] = i;

        for (int j = 1; j < L; j++)
            lift[i][j] = lift[lift[i][j - 1]][j - 1];
    }

    int q;
    cin >> q;

    while (q--) {
        int s, t;
        cin >> s >> t;

        if (r[s] >= t) {
            cout << 1 << '\n';
            continue;
        }

        int ans = 1;
        for (int i = L - 1; ~i; i--) {
            if (r[lift[s][i]] < t)
                ans += (1 << i), s = lift[s][i];
        }
        s = lift[s][0];

        cout << (r[s] >= t ? ans + 1 : -1) << '\n';
    }

    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 8
• Subtask 3: 0 / 11
• Subtask 4: 0 / 25
• Subtask 5: 35 / 35
• Subtask 6: 0 / 13