Submission #1062412

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062412		12345678	Port Facility (JOI17_port_facility)	C++17	10 / 100	1 ms	604 KiB

port_facility

#include <bits/stdc++.h>

using namespace std;

const int nx=2e3+5, mod=1e9+7;

int n, l[nx], r[nx], res=1, cnt, c[nx], f, vs[nx];
vector<int> d[nx];
pair<int, int> v[nx];

void dfs(int u)
{
    vs[u]=1;
    for (auto v:d[u])
    {
        if (vs[v])
        {
            if (c[v]==c[u]) f=1;
            continue;
        }
        c[v]=!c[u];
        dfs(v);
    }
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n;
    for (int i=1; i<=n; i++) cin>>l[i]>>r[i], v[l[i]]={r[i], i}, v[r[i]]={l[i], i};
    for (int i=1; i<=n; i++)
    {
        pair<int, int> mn={1e9, 1e9};
        for (int j=l[i]+1; j<r[i]; j++) mn=min(mn, v[j]);
        pair<int, int> mx={-1e9, 1e9};
        for (int j=l[i]+1; j<r[i]; j++) mx=max(mx, v[j]);
        if (mn.first<l[i]) d[i].push_back(mn.second), d[mn.second].push_back(i);
        if (mx.first>r[i] )d[i].push_back(mx.second), d[mx.second].push_back(i);
    }
    for (int i=1; i<=n; i++) if (!vs[i]) dfs(i), res=(res*2)%mod;
    if (f) cout<<0;
    else cout<<res;
}

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