Submission #471447

#	Time	Username	Problem	Language	Result	Execution time	Memory
471447		Rainbowbunny	Port Facility (JOI17_port_facility)	C++17	22 / 100	39 ms	16564 KiB

port_facility

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

const int MAXN = 2005;
const int mod = 1e9 + 7;

int n, ans = 1;
int c[MAXN];
int A[2 * MAXN], B[2 * MAXN];
vector <int> Adj[MAXN];

void DFS(int node, int color)
{
    c[node] = color;
    for(auto x : Adj[node])
    {
        if(!c[x])
        {
            DFS(x, 3 - color);
        }
        else if(c[x] == c[node])
        {
            cout << 0 << '\n';
            exit(0);
        }
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    if(n > 2000)
    {
        return 0;
    }
    for(int i = 1; i <= n; i++)
    {
        cin >> A[i] >> B[i];
    }
    for(int i = 1; i <= n; i++)
    {
        for(int j = i + 1; j <= n; j++)
        {
            if(A[i] < A[j] and B[i] < B[j] and B[i] > A[j])
            {
                Adj[i].push_back(j);
                Adj[j].push_back(i);
            }
            else if(A[i] > A[j] and B[i] > B[j] and B[j] > A[i])
            {
                Adj[i].push_back(j);
                Adj[j].push_back(i);
            }
        }
    }
    for(int i = 1; i <= n; i++)
    {
        if(!c[i])
        {
            DFS(i, 1);
            ans = ans * 2 % mod;
        }
    }
    cout << ans << '\n';
}

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