Submission #1092927

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092927		Trisanu_Das	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	518 ms	41764 KiB

Main

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

const int Z = 1e5;
const int B = 17;

int N, K, M;

struct SegmentTree {
    int a[2 * Z] = {};
    int minQuery = 0;

    void update(int i, int value) {
        i += N;
        if (minQuery)
            a[i] = max(a[i], Z - value);
        else
            a[i] = max(a[i], value);

        for (i /= 2; i >= 1; i /= 2) {
            a[i] = max(a[2 * i], a[2 * i + 1]);
        }
    }

    int query(int l, int r) {
        int result = 0;
        l += N;
        r += N + 1;

        while (l < r) {
            if (l & 1) result = max(result, a[l++]);
            if (r & 1) result = max(result, a[--r]);
            l /= 2;
            r /= 2;
        }

        return minQuery ? Z - result : result;
    }

    int operator[](int i) {
        return minQuery ? Z - a[i + N] : a[i + N];
    }
} segmentTree[2][B];

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> N >> K >> M;

    priority_queue<array<int, 2>> pq[2];
    vector<array<int, 2>> updates[2][N];

    while (M--) {
        int l, r;
        cin >> l >> r;
        --l, --r;

        if (l < r)
            updates[1][l].push_back({r, min(l + K - 1, r)});
        else
            updates[0][max(l - K + 1, r)].push_back({-r, l});
    }

    for (int i = 0; i < B; ++i) {
        segmentTree[0][i].minQuery = 1;
    }

    for (int i = 0; i < N; ++i) {
        for (int j : {0, 1}) {
            for (auto k : updates[j][i])
                pq[j].push(k);

            while (!pq[j].empty() && pq[j].top()[1] < i)
                pq[j].pop();

            int topVal = pq[j].empty() ? i : (j ? 1 : -1) * pq[j].top()[0];
            segmentTree[j][0].update(i, topVal);
        }
    }

    for (int k = 0; k + 1 < B; ++k) {
        for (int j : {0, 1}) {
            for (int i = 0; i < N; ++i) {
                int left = segmentTree[0][k][i];
                int right = segmentTree[1][k][i];
                segmentTree[j][k + 1].update(i, segmentTree[j][k].query(left, right));
            }
        }
    }
    cin >> M;
    while (M--) {
        int l, t;
        cin >> l >> t;
        --l;
        --t;
        int r = l;
        int steps = 0;
        for (int i = B - 1; i >= 0; --i) {
            int left = segmentTree[0][i].query(l, r);
            int right = segmentTree[1][i].query(l, r);
            if (left > t || t > right) {
                l = left;
                r = right;
                steps |= 1 << i;
            }
        }
        cout << (steps + 1 > N ? -1 : steps + 1) << '\n';
    }
}

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