Submission #1274649

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274649		MisterReaper	Railway Trip 2 (JOI22_ho_t4)	C++20	100 / 100	246 ms	224888 KiB

Main

// File railwaytrip.cpp created on 29.09.2025 at 21:19:43
#include <bits/stdc++.h>

using i64 = long long;

#ifdef DEBUG 
    #include "/home/ahmetalp/Desktop/Workplace/debug.h"
#else
    #define debug(...) void(23)
#endif

template<typename T>
bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template<typename T>
bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

constexpr int max_N = int(1E5) + 5;

int logs[max_N];

struct Pair {
    int l, r;
    Pair() {}
    Pair(int x) : l(x), r(x) {}
    Pair(int x, int y) : l(x), r(y) {}
};
Pair operator+ (const Pair& lhs, const Pair& rhs) {
    Pair res;
    res.l = std::min(lhs.l, rhs.l);
    res.r = std::max(lhs.r, rhs.r);
    return res;
}

struct SparseTable {
    int n;
    std::vector<std::vector<Pair>> mat;
    SparseTable() {}
    void init(std::vector<Pair>& x) {
        n = int(x.size());
        int lg = logs[n] + 1;
        mat.resize(lg);
        mat[0].resize(n);
        for (int i = 0; i < n; ++i) {
            mat[0][i] = x[i];
        }
        for (int i = 1; i < lg; ++i) {
            int m = n - (1 << i) + 1;
            mat[i].resize(m);
            for (int j = 0; j < m; ++j) {
                mat[i][j] = mat[i - 1][j] + mat[i - 1][j + (1 << (i - 1))];
            }
        }
    }
    Pair get(int l, int r) {
        int d = r - l + 1;
        int lg = logs[d];
        return mat[lg][l] + mat[lg][r - (1 << lg) + 1];
    }
};

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

    logs[0] = -1;
    for (int i = 1; i < max_N; ++i) {
        logs[i] = logs[i >> 1] + 1;
    }

    int N, K;
    std::cin >> N >> K;

    int M;
    std::cin >> M;

    std::vector<std::array<int, 2>> A(M);
    for (int i = 0; i < M; ++i) {
        std::cin >> A[i][0] >> A[i][1];
        --A[i][0], --A[i][1];
    }

    const int LG = logs[N] + 1;

    std::vector<SparseTable> gost(LG);
    std::vector<std::vector<Pair>> go(LG, std::vector<Pair>(N));

    {
        std::vector<std::vector<int>> mat(LG, std::vector<int>(N));
        auto update = [&](int a, int b, int x) -> void {
            int d = b - a + 1;
            int lg = logs[d];
            chmax(mat[lg][a], x);
            chmax(mat[lg][b - (1 << lg) + 1], x);
        };
        for (int i = 0; i < M; ++i) {
            int a = A[i][0], b = A[i][1];
            if (a < b) {
                int l = a, r = std::min(b, a + K - 1);
                update(l, r, A[i][1]);
            }
        }
        for(int l = LG - 1; l >= 1; --l) {
            int m = N - (1 << l) + 1;
            for (int i = 0; i < m; ++i) {
                chmax(mat[l - 1][i], mat[l][i]);
                chmax(mat[l - 1][i + (1 << (l - 1))], mat[l][i]);
            }
        }
        for (int i = 0; i < N; ++i) {
            go[0][i].r = std::max(i, mat[0][i]);
        }
    }
    {
        std::vector<std::vector<int>> mat(LG, std::vector<int>(N, N));
        auto update = [&](int a, int b, int x) -> void {
            int d = b - a + 1;
            int lg = logs[d];
            chmin(mat[lg][a], x);
            chmin(mat[lg][b - (1 << lg) + 1], x);
        };
        for (int i = 0; i < M; ++i) {
            int a = A[i][0], b = A[i][1];
            if (a > b) {
                int l = std::max(b, a - K + 1), r = a;
                update(l, r, A[i][1]);
            }
        }
        for(int l = LG - 1; l >= 1; --l) {
            int m = N - (1 << l) + 1;
            for (int i = 0; i < m; ++i) {
                chmin(mat[l - 1][i], mat[l][i]);
                chmin(mat[l - 1][i + (1 << (l - 1))], mat[l][i]);
            }
        }
        for (int i = 0; i < N; ++i) {
            go[0][i].l = std::min(i, mat[0][i]);
        }
    }

    debug("hello");

    for (int l = 0; l < LG; ++l) {
        gost[l].init(go[l]);
        if (l == LG - 1) {
            break;
        }
        for (int i = 0; i < N; ++i) {
            auto rng = go[l][i];
            go[l + 1][i] = gost[l].get(rng.l, rng.r);
        }
    }

    debug("bro");

    int Q;
    std::cin >> Q;

    while (Q--) {
        int S, T;
        std::cin >> S >> T;
        --S, --T;

        debug("?", S, T);

        int ans = 0;

        Pair rng = S;

        for (int l = LG - 1; l >= 0; --l) {
            Pair x = gost[l].get(rng.l, rng.r);
            if (!(x.l <= T && T <= x.r)) {
                ans += 1 << l;
                rng = x;
            } 
        }

        Pair x = gost[0].get(rng.l, rng.r);
        if (!(x.l <= T && T <= x.r)) {
            std::cout << "-1\n";
        } else {
            std::cout << ans + 1 << '\n';
        }
    }

    return 0;
}

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