제출 #797220

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
797220		finn__	L-triominoes (CEOI21_ltriominoes)	C++17	28 / 100	71 ms	596 KiB

ltrominoes

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

constexpr size_t W = 6, K = 250;

struct bmatrix
{
    bitset<1 << W> mat[1 << W];

    bmatrix transpose() const
    {
        bmatrix res;
        for (size_t i = 0; i < 1U << W; ++i)
            for (size_t j = 0; j < 1U << W; ++j)
                res.mat[i][j] = mat[j][i];
        return res;
    }

    bmatrix operator*(bmatrix const &y) const
    {
        bmatrix x = y.transpose();
        bmatrix res;

        for (size_t i = 0; i < 1U << W; ++i)
            for (size_t j = 0; j < 1U << W; ++j)
                res.mat[i][j] = (mat[i] & x.mat[j]).any();

        return res;
    }

    bmatrix pow(size_t n) const
    {
        bmatrix a = *this;
        bmatrix res;
        for (size_t i = 0; i < 1U << W; ++i)
            res.mat[i][i] = 1;

        while (n)
        {
            if (n & 1)
                res = res * a;
            a = a * a;
            n >>= 1;
        }

        return res;
    }

    bitset<1 << W> mul_vec(bitset<1 << W> const &v) const
    {
        bitset<1 << W> res;
        for (size_t i = 0; i < 1U << W; ++i)
            res[i] = (mat[i] & v).any();
        return res;
    }
};

pair<size_t, size_t> p[K];
bitset<1 << W> f[1 << W];
vector<uint32_t> pre[1 << W][1 << W];
bitset<1 << (W << 1)> visited;

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

    size_t w, h, k;
    cin >> w >> h >> k;

    for (size_t i = 0; i < k; ++i)
        cin >> p[i].first >> p[i].second, --p[i].first, --p[i].second;

    for (size_t i = 0; i < 1U << w; ++i)
        f[i][0] = 1;
    for (size_t i = 0; i < 1U << w; ++i)
        for (size_t j = 0; j < 1U << w; ++j)
            if (f[i][j])
                for (size_t h = 0; h < w; ++h)
                    if (!(i & (1 << h)))
                    {
                        if (h && !(j & (1 << h)) && !(j & (1 << (h - 1))))
                        {
                            size_t ni = i ^ (1 << h), nj = j ^ (1 << h) ^ (1 << (h - 1));
                            f[ni][nj] = 1;
                            pre[ni][nj].push_back((i << W) | j);
                        }
                        if (h + 1 < w && !(j & (1 << h)) && !(j & (1 << (h + 1))))
                        {
                            size_t ni = i ^ (1 << h), nj = j ^ (1 << h) ^ (1 << (h + 1));
                            f[ni][j] = 1;
                            pre[ni][nj].push_back((i << W) | j);
                        }
                        if (h + 1 < w && !(i & (1 << (h + 1))) && !(j & (1 << h)))
                        {
                            size_t ni = i ^ (1 << h) ^ (1 << (h + 1)), nj = j ^ (1 << h);
                            f[ni][nj] = 1;
                            pre[ni][nj].push_back((i << W) | j);
                        }
                        if (h + 1 < w && !(i & (1 << (h + 1))) && !(j & (1 << (h + 1))))
                        {
                            size_t ni = i ^ (1 << h) ^ (1 << (h + 1)), nj = j ^ (1 << (h + 1));
                            f[ni][nj] = 1;
                            pre[ni][nj].push_back((i << W) | j);
                        }
                    }

    bmatrix transitions;
    for (size_t i = 0; i < 1 << w; ++i)
    {
        queue<uint32_t> q;
        q.push((((1 << w) - 1) << W) | i);
        visited.reset();

        while (!q.empty())
        {
            uint32_t u = q.front();
            q.pop();

            if (!(u & ((1 << W) - 1)))
            {
                transitions.mat[i][u >> W] = 1;
            }

            for (auto const &v : pre[u >> W][u & ((1 << W) - 1)])
                if (!visited[v])
                {
                    q.push(v);
                    visited[v] = 1;
                }
        }
    }

    sort(p, p + k, [](auto const &a, auto const &b)
         { return a.second < b.second; });
    bitset<1 << W> state, state2;
    size_t i = 0, pos = 0;
    if (k && !p[0].second)
    {
        size_t x = 0;
        while (!p[i].second)
            x |= 1 << p[i].first, ++i;
        state[x] = 1;
    }
    else
        state[0] = 1;

    while (i < k)
    {
        state = transitions.pow(p[i].second - pos).mul_vec(state);
        pos = p[i].second;
        size_t x = 0;
        size_t j = i;
        while (j < k && p[j].second == p[i].second)
            x |= 1 << p[j].first, ++j;
        i = j;

        state2.reset();
        for (size_t i = 0; i < 1 << w; ++i)
            if (!(i & x) && state[i])
                state2[i ^ x] = 1;
        state = state2;
    }

    if (pos != h - 1)
    {
        state = transitions.pow(h - 1 - pos).mul_vec(state);
    }

    cout << (state[(1 << w) - 1] ? "YES" : "NO") << '\n';
}

컴파일 시 표준 에러 (stderr) 메시지

ltrominoes.cpp: In function 'int main()':
ltrominoes.cpp:109:26: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  109 |     for (size_t i = 0; i < 1 << w; ++i)
      |                        ~~^~~~~~~~
ltrominoes.cpp:159:30: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  159 |         for (size_t i = 0; i < 1 << w; ++i)
      |                            ~~^~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 7
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 0 / 35
• Subtask 6: 0 / 20