Submission #997393

#	Time	Username	Problem	Language	Result	Execution time	Memory
997393		Sharky	Port Facility (JOI17_port_facility)	C++17	22 / 100	6096 ms	24484 KiB

port_facility

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

#define int long long
const int mod = 1e9+7;

const int N = 1000001;
int n, p[N << 1], sz[N << 1], conn = 0, ans = 1, clr[N << 1];
vector<int> f;
set<int> disc;

int find(int u) {
    return p[u] == u ? u : p[u] = find(p[u]);
}

void merge(int u, int v) {
    u = find(u), v = find(v);
    if (u == v) return;
    if (sz[u] < sz[v]) swap(u, v);
    p[v] = u, sz[u] += sz[v];
}

struct SegTree {
    int size = 1;
    vector<pair<int, int>> seg;
    void init(int _n) {
        for (; size < _n;) size *= 2;
        seg.assign(2 * size + 10, {0, 0});
    }
    void update(int pos, int v, int l, int r, int id, bool d = 0) {
        if (l == r) {
            if (!d) {
                seg[id].first = 1;
                seg[id].second = v;
            } else seg[id].first = seg[id].second = 0;
            return;
        }
        int mid = (l + r) / 2;
        if (pos <= mid) update(pos, v, l, mid, id * 2, d);
        else update(pos, v, mid + 1, r, id * 2 + 1, d);
        seg[id].first = seg[id * 2].first + seg[id * 2 + 1].first;
    }
    void dive(int i, int qr, int l, int r, int id) {
        if (qr < l || r < 1 || l > r || !seg[id].first) return;
        if (l == r) {
            merge(i, seg[id].second + n);
            merge(i + n, seg[id].second);
            if (find(i) == find(i + n) || find(seg[id].second) == find(seg[id].second + n)) {
                cout << "0\n";
                exit(0);
            }
            return;
        }
        int mid = (l + r) / 2;
        if (seg[id * 2].first) dive(i, qr, l, mid, id * 2);
        if (seg[id * 2 + 1].first) dive(i, qr, mid + 1, r, id * 2 + 1);
    }
} st;

int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= (n << 1); i++) p[i] = i, sz[i] = 1;
    vector<pair<int, int>> p(n);
    for (auto& [x, y] : p) {
        cin >> x >> y;
        clr[y] = 1;
    }
    sort(p.begin(), p.end());
    st.init(2 * n + 1);
    for (int i = 0; i < n; i++) {
        if (i) for (int j = p[i - 1].first; j < p[i].first; j++) {
            if (clr[j]) {
                st.update(j, 0, 1, 2 * n, 1, 1);
            }
        }
        st.dive(i + 1, p[i].second - 1, 1, 2 * n, 1);
        st.update(p[i].second, i + 1, 1, 2 * n, 1);
    }
    for (int i = 1; i <= n; i++) if (find(i) == find(i + n)) {
        cout << "0\n";
        return 0;
    }
    for (int i = 1; i <= 2 * n; i++) {
        int x = find(i);
        if (x > n) x -= n;
        disc.insert(x);
    }
    conn = disc.size();
    for (int i = 1; i <= conn; i++) ans = ans * 2 % mod;
    cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22