Submission #294650

#	Time	Username	Problem	Language	Result	Execution time	Memory
294650		Denisov	Furniture (JOI20_furniture)	C++14	100 / 100	469 ms	20032 KiB

furniture

#include <bits/stdc++.h>
#include <ext/rope>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#define int long long
#define pb push_back
#define x first
#define y second
#define mk(a,b) make_pair(a,b)
#define rr return 0
#define sqr(a) ((a)*(a))
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()

using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

template<class value, class cmp = less<value> >
using ordered_set = tree<value, null_type, cmp, rb_tree_tag, tree_order_statistics_node_update>;
template<class value, class cmp = less_equal<value> >
using ordered_multiset = tree<value, null_type, cmp, rb_tree_tag, tree_order_statistics_node_update>;
template<class key, class value, class cmp = less<key> >
using ordered_map = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;

/// find_by_order()
/// order_of_key()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int randll(int l = INT_MIN, int r = INT_MAX) {
    return uniform_int_distribution<int>(l, r)(rng);
}
const int INF = 1e9, MOD = 1e9 + 7; /// think
const ll LINF = 1e18;


const int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
inline bool inside (int x, int y, int n, int m) {
    return 0 <= x && 0 <= y && x < n && y < m;
}

template<class T> bool umin (T &a, T b) {return a > b ? (a = b, true) : false; }
template<class T> bool umax (T &a, T b) {return a < b ? (a = b, true) : false; }


main()
{
//    freopen("output.txt", "w", stdout);
    ios::sync_with_stdio(0);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, m, x;
    cin >> n >> m;
//    n = m = 100;
    vector <vector <int> > a(n, vector <int> (m));
    vector <vector <int> > used(n, vector <int> (m));
    vector <int> f(n);
    vector <int> l(m);
    int cnt = 0;
    function<bool(int, int)> go = [&] (int x, int y) {
        if (x == n - 1 && y == m - 1) return true;
        if (x >= n || y >= m) return false;
        if (a[x][y]) return false;
        if (y >= m - f[x]) return false;
        if (used[x][y] == cnt) return false;
        used[x][y] = cnt;
        if (go(x, y + 1)) {
            return true;
        }
        if (go(x + 1, y)) {
            f[x] = m - y - 1;
            return true;
        }
        return false;
    };
    function<bool(int, int)> go1 = [&] (int x, int y) {
        if (x == n - 1 && y == m - 1) return true;
        if (x >= n || y >= m) return false;
        if (a[x][y]) return false;
        if (x >= n - l[y]) return false;
        if (used[x][y] == cnt) return false;
        used[x][y] = cnt;
        if (go1(x + 1, y)) {
            return true;
        }
        if (go1(x, y + 1)) {
            l[y] = n - x - 1;
            return true;
        }
        return false;
    };
    auto upd = [&] (int x, int y) {
        if (m - 1 - (x ? f[x - 1] : m - 1) <= y && y <= m - 1 - f[x] &&
            n - 1 - (y ? l[y - 1] : n - 1) <= x && x <= n - 1 - l[y]) {
                return false;
            }
        if (m - 1 - (x ? f[x - 1] : m - 1) <= y && y <= m - 1 - f[x]) {
            if (x == n - 1) assert(false);
            a[x][y] = 1;
            f[x] = m - y;
            int X = x;
            ++cnt;
            int Y = y - 1;
            while (true) {
                f[X] = m - Y - 1;
                while (X > 0 && f[X] > f[X - 1]) {
                    f[X - 1] = f[X];
                    --X;
                }
                assert(Y >= 0);
                if (go(X, Y)) {
                    return true;
                }
                --Y;
            }
        }
        if (n - 1 - (y ? l[y - 1] : n - 1) <= x && x <= n - 1 - l[y]) {
            a[x][y] = 1;
            ++cnt;
            l[y] = n - x;
            int X = x - 1, Y = y;
            while (true) {
                l[Y] = n - X - 1;
                while (Y > 0 && l[Y] > l[Y - 1]) {
                    l[Y - 1] = l[Y];
                    --Y;
                }
                assert(X >= 0);
                if (go1(X, Y)) {
                    return true;
                }
                --X;
            }
        }
        a[x][y] = 1;
        return true;
    };
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> x;
            if (x) {
                assert(upd(i, j));
            }
        }
    }
    int q, y;
    auto solve = [&] () {
        vector <vector <int> > dp(n, vector <int> (m));
        dp[0][0] = 1;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (a[i][j]) continue;
                if (i + 1 < n) {
                    umax(dp[i + 1][j], dp[i][j]);
                }
                if (j + 1 < m) {
                    umax(dp[i][j + 1], dp[i][j]);
                }
            }
        }
        return bool(dp[n - 1][m - 1]);
    };
    cin >> q;
//    q = n * m;
    while (q--) {
        cin >> x >> y;
//        x = randll(1, n), y = randll(1, m);
        --x, --y;
//        while (a[x][y] || (x == n - 1 && y == m - 1) || (x == 0 && y == 0)) {
//            x = randll(0, n - 1);
//            y = randll(0, m - 1);
//        }
//        cout << x << ' ' << y << '\n';
//        a[x][y] = 1;
//        int v = solve();
//        a[x][y] = 0;
        int V = upd (x, y);
//        if (V != v) {
//            cout << "bad " << v << ' ' << V << '\n';
//            for (auto &i : f) {
//                cout << i << ' ';
//            }
//            cout << '\n';
//            rr;
//        }
        cout << V << '\n';
    }
}

Compilation message (stderr)

furniture.cpp:53:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   53 | main()
      |      ^
furniture.cpp: In function 'int main()':
furniture.cpp:155:10: warning: variable 'solve' set but not used [-Wunused-but-set-variable]
  155 |     auto solve = [&] () {
      |          ^~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95