제출 #986788

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
986788		alextodoran	Port Facility (JOI17_port_facility)	C++17	22 / 100	31 ms	18004 KiB

port_facility

/**
 _  _   __  _ _ _  _  _ _
 |a  ||t  ||o    d | |o  |
| __    _| | _ | __|  _ |
| __ |/_  | __  /__\ / _\|

**/

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N_MAX = 2000;
const int MOD = (int) 1e9 + 7;

int N;
int L[N_MAX + 2], R[N_MAX + 2];

vector <int> adj[N_MAX + 2];

int color[N_MAX + 2];

void dfs (int u) {
    for (int v : adj[u]) {
        if (color[v] == 0) {
            color[v] = 3 - color[u];
            dfs(v);
        } else if (color[v] != 3 - color[u]) {
            cout << 0 << "\n";
            exit(0);
        }
    }
}

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> N;
    for (int i = 1; i <= N; i++) {
        cin >> L[i] >> R[i];
    }
    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            if (L[i] < L[j] && L[j] < R[i] && R[i] < R[j]) {
                adj[i].push_back(j);
                adj[j].push_back(i);
            }
        }
    }
    int answer = 1;
    for (int i = 1; i <= N; i++) {
        if (color[i] == 0) {
            color[i] = 1;
            dfs(i);
            answer = answer * 2 % MOD;
        }
    }
    cout << answer << "\n";

    return 0;
}

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