Submission #953958

#	Time	Username	Problem	Language	Result	Execution time	Memory
953958		Pring	Port Facility (JOI17_port_facility)	C++17	10 / 100	35 ms	68188 KiB

port_facility

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

#ifdef MIKU
string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << "[" << #x << "]: ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif

#define int long long
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
typedef pair<int, int> pii;

const int MXN = 2000005, mod = 1000000007;
int n, a[MXN];
pii p[MXN];
int N;
bitset<MXN> b;
vector<pii> st;

void PCOUT(priority_queue<pii> &pq) {
    vector<pii> v;
    cout << "PQ: ";
    while (pq.size()) {
        cout << '<' << pq.top().fs << ' ' << pq.top().sc << "> ";
        v.push_back(pq.top());
        pq.pop();
    }
    cout << endl;
    for (auto &i : v) pq.push(i);
}

void MERGE(priority_queue<pii> &a, priority_queue<pii> &b) {
    if (a.size() < b.size()) swap(a, b);
    while (b.size()) {
        a.push(b.top());
        b.pop();
    }
}

void UPDATE(priority_queue<pii> &pq) {
    while (pq.size() && !b[pq.top().sc]) pq.pop();
}

struct DSU {
    int p[MXN], nc;
    priority_queue<pii> pq[MXN];

    void init(int n) {
        fill(p + 1, p + n + 1, -1);
        nc = n;
    }

    int find(int x) {
        return (p[x] < 0 ? x : p[x] = find(p[x]));
    }

    bool onion(int x, int y) {
        // debug("onion", x, y);
        x = find(x);
        y = find(y);
        // debug("onion", x, y);
        if (x == y) {
            // cout << "PRING" << '\n';
            return false;
        }
        if (p[x] > p[y]) swap(x, y);
        p[x] += p[y];
        p[y] = x;
        // debug("MERGE", x, y);
        MERGE(pq[x], pq[y]);
        nc--;
        return true;
    }
} dsu;

void ADD(int l, int id) {
    // debug("ADD", id);
    st.push_back(mp(l, id));
    dsu.pq[id].push(mp(l, id));
    b[id] = true;
}

void REMOVE(int l, int r, int id) {
    // debug("REM", id);
    while (st.size() && st.back().fs >= l) {
        auto [l2, id2] = st.back();
        if (id2 != id) {
            dsu.onion(id, id2 + n);
            dsu.onion(id + n, id2);
        }
        st.pop_back();
    }
    b[id] = false;
    UPDATE(dsu.pq[dsu.find(id)]);
    if (dsu.pq[dsu.find(id)].size()) st.push_back(dsu.pq[dsu.find(id)].top());
    UPDATE(dsu.pq[dsu.find(id + n)]);
    if (dsu.pq[dsu.find(id + n)].size()) st.push_back(dsu.pq[dsu.find(id + n)].top());
}

int POW(int a, int b) {
    int ans = 1;
    for (int i = 1 << 20; i > 0; i >>= 1) {
        ans = ans * ans % mod;
        if (i & b) ans = ans * a % mod;
    }
    return ans;
}

int miku() {
    cin >> n;
    N = n * 2;
    FOR(i, 1, n + 1) {
        cin >> p[i].fs >> p[i].sc;
        a[p[i].fs] = i;
        a[p[i].sc] = -i;
    }
    dsu.init(N);
    FOR(i, 1, N + 1) {
        if (a[i] > 0) {
            ADD(i, a[i]);
        } else {
            REMOVE(p[-a[i]].fs, p[-a[i]].sc, -a[i]);
        }
        // for (auto &i : st) cout << i.fs << ' ' << i.sc << endl;
    }
    FOR(i, 1, n) if (dsu.find(i) == dsu.find(i + n)) return 0;
    return POW(2, dsu.nc / 2);
}

int32_t main() {
    cin.tie(0) -> sync_with_stdio(false);
    cin.exceptions(cin.failbit);
    cout << miku() << '\n';
    return 0;
}

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