Submission #617491

#	Time	Username	Problem	Language	Result	Execution time	Memory
617491		dxz05	L-triominoes (CEOI21_ltriominoes)	C++14	100 / 100	2245 ms	13328 KiB

ltrominoes

//#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
//#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 998244353;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 3e2;
const int M = 1555;

int n;
vector<vector<int>> arr;

set<int> s;
void rec(int x){
    if (x == n){
        int cur = 0;
        for (int i = 0; i < n; i++){
            for (int j = 0; j < 2; j++){
                int k = i * 2 + j;
                if (arr[i][j]) cur += (1 << k);
            }
        }
        s.insert(cur);
        return;
    }

    rec(x + 1);

    if (x + 1 < n && arr[x][0] == 0 && arr[x][1] == 0 && arr[x + 1][0] == 0){
        arr[x][0] = 1;
        arr[x][1] = 1;
        arr[x + 1][0] = 1;
        rec(x + 1);
        arr[x][0] = 0;
        arr[x][1] = 0;
        arr[x + 1][0] = 0;
    }

    if (x + 1 < n && arr[x][0] == 0 && arr[x][1] == 0 && arr[x + 1][1] == 0){
        arr[x][0] = 1;
        arr[x][1] = 1;
        arr[x + 1][1] = 1;
        rec(x + 1);
        arr[x][0] = 0;
        arr[x][1] = 0;
        arr[x + 1][1] = 0;
    }

    if (x + 1 < n && arr[x][0] == 0 && arr[x + 1][0] == 0 && arr[x + 1][1] == 0){
        arr[x][0] = 1;
        arr[x + 1][0] = 1;
        arr[x + 1][1] = 1;
        rec(x + 1);
        arr[x][0] = 0;
        arr[x + 1][0] = 0;
        arr[x + 1][1] = 0;
    }

    if (x - 1 >= 0 && arr[x][0] == 0 && arr[x - 1][1] == 0 && arr[x][1] == 0){
        arr[x][0] = 1;
        arr[x - 1][1] = 1;
        arr[x][1] = 1;
        rec(x + 1);
        arr[x][0] = 0;
        arr[x - 1][1] = 0;
        arr[x][1] = 0;
    }

}

vector<int> g[1 << 13];

void build_graph(){
    arr.resize(n, vector<int>(2));
    rec(0);
    for (int x : s){
        int maskl = 0, maskr = 0;
        for (int i = 0; i < n; i++){
            if (x & (1 << (2 * i))) maskl |= (1 << i);
            if (x & (1 << (2 * i + 1))) maskr |= (1 << i);
        }
        g[maskl].push_back(maskr);
    }
}

void out(int mask){
    for (int i = 0; i < n; i++){
        if (mask & (1 << i)) {
            cout << 1;
        } else {
            cout << 0;
        }
    }
    cout << endl;
}

bool triominoes(vector<vector<bool>> stone){
    int m = (int)stone[0].size();

    vector<vector<bool>> dp(m, vector<bool>(1 << n));
    for (int x = 0; x < (1 << n); x++){
        for (int y : g[x]){
            bool ok = true;
            for (int j = 0; j < n; j++){
                bool s0 = (x & (1 << j));
                bool s1 = (y & (1 << j));
                if (stone[j][0] && s0) ok = false;
                if (stone[j][1] && s1) ok = false;
                if (!stone[j][0] && !s0) ok = false;
            }
            if (ok) dp[1][y] = true;
        }
    }

    for (int i = 1; i + 1 < m; i++){
        for (int x = 0; x < (1 << n); x++){
            if (!dp[i][x]) continue;
            int xx = 0;
            for (int j = 0; j < n; j++){
                if (!(x & (1 << j)) && !stone[j][i]) xx |= (1 << j);
            }
            for (int y : g[xx]){
                bool ok = true;
                for (int j = 0; j < n; j++){
                    bool s1 = (y & (1 << j));
                    if (stone[j][i + 1] && s1) ok = false;
                }
                if (ok){
                    dp[i + 1][y] = true;
                }
            }
        }
    }

    int full = 0;
    for (int i = 0; i < n; i++){
        if (!stone[i][m - 1]) full |= (1 << i);
    }

    return dp[m - 1][full];
}

void solve(int TC) {
    int m, k;
    cin >> n >> m >> k;

    build_graph();

    vector<pair<int, int>> stones;

    set<int> pos = {0, m - 1};
    while (k--){
        int x, y;
        cin >> x >> y;
        --x, --y;
        stones.emplace_back(x, y);
        pos.insert(y);
    }

    vector<int> vec;
    for (int x : pos) vec.push_back(x);
    vector<int> diff;
    for (int i = 0; i + 1 < vec.size(); i++) diff.push_back(vec[i + 1] - vec[i]);

    map<int, int> mp;
    mp[0] = 0;
    int sum = 0;
    for (int i = 0; i < diff.size(); i++){
        if (diff[i] > 12) diff[i] = 6 + diff[i] % 6;
        sum += diff[i];
        mp[vec[i + 1]] = sum;
    }

    m = sum + 1;

    vector<vector<bool>> stone(n, vector<bool>(m, false));
    for (auto now : stones){
        int x = now.first, y = now.second;
        y = mp[y];
//        cout << x << ' ' << y << endl;
        stone[x][y] = true;
    }

    bool ans = triominoes(stone);

    cout << (ans ? "YES" : "NO");

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

#ifdef dddxxz
    freopen("input.txt", "rg", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

#ifdef dddxxz
    cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message (stderr)

ltrominoes.cpp: In function 'void solve(int)':
ltrominoes.cpp:197:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  197 |     for (int i = 0; i + 1 < vec.size(); i++) diff.push_back(vec[i + 1] - vec[i]);
      |                     ~~~~~~^~~~~~~~~~~~
ltrominoes.cpp:202:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  202 |     for (int i = 0; i < diff.size(); i++){
      |                     ~~^~~~~~~~~~~~~

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