Submission #210429

#	Time	Username	Problem	Language	Result	Execution time	Memory
210429		dolphingarlic	Port Facility (JOI17_port_facility)	C++14	0 / 100	5 ms	376 KiB

port_facility

#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;

const ll MOD = 1e9 + 7;

pair<int, int> a[1000000];
int cmp[1000000], cnt;

int find(int A) {
    while (A != cmp[A]) cmp[A] = cmp[cmp[A]], A = cmp[A];
    return A;
}

bool onion(int A, int B) {
    A = find(A), B = find(B);
    if (A == B) return false;
    cmp[A] = B;
    cnt--;
    return true;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n;
    cin >> n;
    FOR(i, 0, n) cin >> a[i].first >> a[i].second;
    sort(a, a + n);

    cnt = n;
    iota(cmp, cmp + n, 0);

    set<pair<int, int>> s;
    FOR(i, 0, n) {
        while (s.size() && (*s.begin()).first < a[i].first) s.erase(s.begin());
        for (pair<int, int> j : s) {
            if (j.first > a[i].second) break;
            if (!onion(i, j.second)) return cout << "0\n", 0;
        }
        s.insert({a[i].second, i});
    }

    ll ans = 1;
    FOR(i, 0, cnt) ans = (ans * 2) % MOD;
    cout << ans << '\n';
    return 0;
}

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