Submission #896851

#	Time	Username	Problem	Language	Result	Execution time	Memory
896851		Alihan_8	Port Facility (JOI17_port_facility)	C++17	0 / 100	1 ms	344 KiB

port_facility

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

const int Mod = 1e9 + 7;

const int N = 2e3 + 1;

bitset <N> b[N];

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n; cin >> n;
    vector <ar<int,2>> a(n);
    for ( auto &[l, r]: a ){
        cin >> l >> r;
    }
    auto in = [&](int i, int j){
        return a[i][0] <= a[j][0] && a[i][1] >= a[j][1];
    };
    sort(all(a));
    for ( int i = 0; i < n; i++ ){
        for ( int j = 0; j < n; j++ ){
            if ( i == j ){
                continue;
            }
            bool flg = (a[i][0] > a[j][1] || a[i][1] < a[j][0]);
            flg |= in(i, j) | in(j, i);
            b[i][j] = !flg;
        }
    }
    for ( int i = 0; i < n; i++ ){
        for ( int j = i + 1; j < n; j++ ){
            if ( b[i][j] && (b[i] & b[j]).count() ){
                return cout << "0\n", 0;
            }
        }
    }
    int ans = 1;
    set <int> st;
    for ( auto &[l, r]: a ){
        auto it = st.lower_bound(l);
        if ( !(it != st.end() && *it < r) ){
            ans = ans * 2 % Mod;
        }
        st.insert(r);
    }
    cout << ans;

    cout << '\n';
}

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