Submission #800621

#	Time	Username	Problem	Language	Result	Execution time	Memory
800621		Johann	L-triominoes (CEOI21_ltriominoes)	C++14	17 / 100	16 ms	944 KiB

ltrominoes

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

typedef long long ll;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

const int maxW = 13;

typedef bitset<1 << maxW> bs;
typedef vector<bs> vbs;
typedef vector<vbs> vvbs;

int W, H, K;
map<int, int> blocked;
vbs mod;
vi group;
vi degin, degout, deg;
vvi adj;

void dfs(int idx, int base, int next, set<int> &nextdp)
{
    if (idx == W)
    {
        nextdp.insert(next);
        return;
    }
    if (base & (1 << idx))
        dfs(idx + 1, base, next, nextdp);
    else
    {
        // _X my pos: 1 << idx

        // TT
        // _T
        if (idx < W - 1 && ((3 << idx) & next) == 0)
            dfs(idx + 1, base | (1 << idx), next | (3 << idx), nextdp);

        // _TT
        // _T_
        if (idx > 0 && ((3 << (idx - 1)) & next) == 0)
            dfs(idx + 1, base | (1 << idx), next | (3 << (idx - 1)), nextdp);

        // T_
        // TT
        if (idx < W - 1 && (base & (3 << idx)) == 0 && (next & (2 << idx)) == 0)
            dfs(idx + 2, base | (3 << idx), next | (2 << idx), nextdp);

        // _T
        // TT
        if (idx < W - 1 && (base & (3 << idx)) == 0 && (next & (1 << idx)) == 0)
            dfs(idx + 2, base | (3 << idx), next | (1 << idx), nextdp);
    }
}

void step(bs &base, int block = 0)
{
    bs re = 0;
    for (int j = 0; j < 1 << W; ++j)
    {
        if (!base[j])
            continue;
        if (j & block)
            continue;

        for (int u : adj[j | block])
            re[u] = 1;
    }
    swap(base, re);
}

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

    cin >> W >> H >> K;
    for (int k = 0, x, y; k < K; ++k)
    {
        cin >> x >> y;
        --x, --y;
        blocked[y] = blocked[y] | (1 << x);
    }

    degin.assign(1 << W, 0), degout.assign(1 << W, 0), deg.assign(1 << W, 0);
    adj.resize(1 << W);
    for (int i = 0; i < 1 << W; ++i)
    {
        set<int> tmp;
        dfs(0, i, 0, tmp);
        degout[i] = sz(tmp);
        for (int u : tmp)
            adj[i].push_back(u), ++degin[u];
    }
    for (int i = 0; i < 1 << W; ++i)
        deg[i] = max(degin[i], degout[i]);

    group.assign(1 << W, -1);
    mod.assign(3, 0);
    if (W % 3 == 0)
    {
        int idx = 0;
        for (int i = 0; i < 1 << W; ++i)
        {
            if (group[i] != -1 || degout[i] == 0)
                continue;
            bs start = 0;
            start[i] = 1;
            for (int j = 0; j < 12; ++j)
                step(start);

            mod[idx] = start;
            for (int j = 0; j < (1 << W); ++j)
                if (start[j])
                    group[j] = idx;
            ++idx;
        }
        assert(idx == 3);
    }
    else
    {
        bs start = 0;
        start[0] = 1;
        for (int j = 0; j < 12; ++j)
            step(start);

        for (int idx = 0; idx < 3; ++idx)
        {
            for (int i = 0; i < 1 << W; ++i)
                if (start[i])
                    group[i] = idx;
            mod[idx] = start;
            step(start);
        }
    }

    bs start = 0;
    start[0] = 1;
    blocked[H - 1] = blocked[H - 1] | 0;
    int h = 0;
    for (pii p : blocked)
    {
        int delta = p.first - h;
        if (delta >= 11)
        {
            set<int> G;
            if (W % 3 == 0)
            {
                for (int i = 0; i < 1 << W; ++i)
                    if (start[i])
                        G.insert(group[i]);
            }
            else
            {
                for (int i = 0; i < 1 << W; ++i)
                    if (start[i])
                        G.insert((group[i] + delta) % 3);
            }
            start = 0;
            for (int g : G)
                start |= mod[g];
            h = p.first;
        }
        else
        {
            for (; h < p.first; ++h)
                step(start);
        }
        step(start, p.second);
        ++h;
    }

    if (start[0])
        cout << "YES\n";
    else
        cout << "NO\n";

    return 0;
}

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