Submission #815288

#	Time	Username	Problem	Language	Result	Execution time	Memory
815288		finn__	Chess Rush (CEOI20_chessrush)	C++17	73 / 100	1039 ms	5260 KiB

chessrush

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

constexpr size_t N = 100;
constexpr int64_t INF = 1LL << 42, MOD = 1000000007;

template <size_t L>
struct Matrix
{
    int64_t m[L][L][2];

    Matrix operator*(Matrix const &b) const
    {
        Matrix c;
        for (size_t i = 0; i < L; ++i)
            for (size_t j = 0; j < L; ++j)
                c.m[i][j][0] = INF, c.m[i][j][1] = 0;

        for (size_t i = 0; i < L; ++i)
            for (size_t j = 0; j < L; ++j)
                for (size_t k = 0; k < L; ++k)
                {
                    if (m[i][k][0] + b.m[k][j][0] < c.m[i][j][0])
                        c.m[i][j][0] = m[i][k][0] + b.m[k][j][0], c.m[i][j][1] = 0;
                    if (m[i][k][0] + b.m[k][j][0] == c.m[i][j][0])
                        c.m[i][j][1] = (c.m[i][j][1] + m[i][k][1] * b.m[k][j][1]) % MOD;
                }

        return c;
    }

    array<int64_t[2], L> operator*(array<int64_t[2], L> const &b)
    {
        array<int64_t[2], L> c;
        for (size_t i = 0; i < L; ++i)
            c[i][0] = INF, c[i][1] = 0;

        for (size_t i = 0; i < L; ++i)
            for (size_t j = 0; j < L; ++j)
            {
                if (m[i][j][0] + b[j][0] < c[i][0])
                    c[i][0] = m[i][j][0] + b[j][0], c[i][1] = 0;
                if (m[i][j][0] + b[j][0] == c[i][0])
                    c[i][1] = (c[i][1] + m[i][j][1] * b[j][1]) % MOD;
            }

        return c;
    }
};

template <typename T>
T binary_exp(T x, T y)
{
    T z = 1;

    while (y)
    {
        if (y & 1)
            z = (z * x) % MOD;
        x = (x * x) % MOD;
        y >>= 1;
    }

    return z;
}

template <typename T>
T modular_inverse(T x) { return binary_exp(x, MOD - 2); }

Matrix<2 * N> bpow[31];
Matrix<N> kpow[31];

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

    int r, c, q;
    cin >> r >> c >> q;

    // Build king matrix for king

    for (size_t i = 0; i < N; ++i)
        for (size_t j = 0; j < N; ++j)
        {
            kpow[1].m[i][j][0] = INF;
            kpow[1].m[i][j][1] = 0;
        }

    for (int i = 0; i < c; ++i)
        for (int j = 0; j < c; ++j)
            kpow[1].m[i][j][0] = kpow[1].m[i][j][1] = max(1, abs(i - j));

    for (size_t i = 2; i < 31; ++i)
        kpow[i] = kpow[i - 1] * kpow[i - 1];

    while (q--)
    {
        char type;
        int start, finish;
        cin >> type >> start >> finish;

        switch (type)
        {
        case 'P':
        {
            if (start == finish)
                cout << r - 1 << " 1\n";
            else
                cout << "0 0\n";
            break;
        }
        case 'R':
        {
            if (start == finish)
                cout << "1 1\n";
            else
                cout << "2 2\n";
            break;
        }
        case 'Q':
        {
            if (start == finish || abs(start - finish) == (r - 1))
                cout << "1 1\n";
            else
            {
                int ans = 4 + (r == c) * ((start == 1 || start == c) + (finish == 1 || finish == c));
                if ((r - abs(start - finish)) & 1)
                {
                    int side_space = (r - 1 - abs(start - finish)) / 2;
                    ans += min(start, finish) - side_space >= 1;
                    ans += max(start, finish) + side_space <= c;
                }
                cout << "2 " << ans << '\n';
            }
            break;
        }
        case 'B':
        {
            if (!((r - abs(start - finish)) & 1))
            {
                cout << "0 0\n";
                break;
            }

            if (abs(start - finish) == r - 1)
            {
                cout << "1 1\n";
                break;
            }

            // Solve for the case when the first move is to the right, then just swap positions
            auto solve_bishop = [&]()
            {
                if (start == c)
                    return make_pair((int64_t)INF, (int64_t)0);
                int64_t moves = 1 + (r - 1 - (c - start) + c - 2) / (c - 1),
                        t = (((r - 1 - (c - start) + c - 2) / (c - 1) - 1) & 1) ? 1 : c;
                bool last_dir = t == 1;
                t += (last_dir ? 1 : -1) * (r - 1 - (c - 1) * (moves - 2) - (c - start));
                if (t == finish)
                    return make_pair(moves, int64_t(1));

                int64_t f;
                if ((finish > t && last_dir) || (finish < t && !last_dir))
                {
                    f = abs(t - finish) / 2;
                }
                else
                {
                    ++moves;
                    if (last_dir)
                        f = c - (t + finish) / 2;
                    else
                        f = (t + finish) / 2 - 1;
                }

                int64_t num_ways = 1;
                for (int64_t i = 0; i < f; ++i)
                    num_ways = (num_ways * (moves - 1 + i)) % MOD;
                int64_t factorial = 1;
                for (int64_t i = 2; i <= f; ++i)
                    factorial = (factorial * i) % MOD;
                num_ways = (num_ways * modular_inverse(factorial)) % MOD;

                return make_pair(moves, num_ways);
            };

            auto [dis_right, ways_right] = solve_bishop();
            start = c - start + 1;
            finish = c - finish + 1;
            auto [dis_left, ways_left] = solve_bishop();

            int64_t dis = min(dis_left, dis_right);
            int64_t ways = 0;
            if (dis == dis_left)
                ways += ways_left;
            if (dis == dis_right)
                ways += ways_right;

            cout << dis << ' ' << ways % MOD << '\n';
            break;
        }
        case 'K':
        {
            array<int64_t[2], N> state;
            for (size_t i = 0; i < N; ++i)
                state[i][0] = INF, state[i][1] = 0;
            state[start - 1][0] = 0;
            state[start - 1][1] = 1;

            size_t k = r - 1, i = 1;
            while (k)
            {
                if (k & 1)
                    state = kpow[i] * state;
                ++i;
                k >>= 1;
            }

            cout << state[finish - 1][0] << ' ' << state[finish - 1][1] << '\n';
            break;
        }
        }
    }
}

• Subtask 1: 0 / 0
• Subtask 2: 8 / 8
• Subtask 3: 15 / 15
• Subtask 4: 22 / 22
• Subtask 5: 5 / 5
• Subtask 6: 8 / 8
• Subtask 7: 15 / 15
• Subtask 8: 0 / 20
• Subtask 9: 0 / 7