Submission #827059

#	Time	Username	Problem	Language	Result	Execution time	Memory
827059		Hanksburger	Passport (JOI23_passport)	C++17	40 / 100	2111 ms	965952 KiB

passport

#include <bits/stdc++.h>
using namespace std;
int dist[2505][2505], rdist[2505][2505], ans[200005];
vector<int> adj[200005], radj[200005];
queue<int> q;
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, m, val;
    cin >> n;
    for (int i=1; i<=n; i++)
    {
        int l, r;
        cin >> l >> r;
        for (int j=l; j<=r; j++)
        {
            adj[i].push_back(j);
            radj[j].push_back(i);
        }
    }
    cin >> m >> val;
    for (int i=1; i<=n; i++)
    {
        if (i!=1 && i!=n && i!=val)
            continue;
        for (int j=1; j<=n; j++)
            dist[i][j]=1e8;
        dist[i][i]=0;
        q.push(i);
        while (!q.empty())
        {
            int u=q.front();
            q.pop();
            for (int v:adj[u])
            {
                if (dist[i][u]+1<dist[i][v])
                {
                    dist[i][v]=dist[i][u]+1;
                    q.push(v);
                }
            }
        }
        for (int j=1; j<=n; j++)
            rdist[i][j]=1e8;
        rdist[i][i]=0;
        q.push(i);
        while (!q.empty())
        {
            int u=q.front();
            q.pop();
            for (int v:radj[u])
            {
                if (rdist[i][u]+1<rdist[i][v])
                {
                    rdist[i][v]=rdist[i][u]+1;
                    q.push(v);
                }
            }
        }
    }
    for (int i=1; i<=n; i++)
    {
        if (i!=val)
            continue;
        ans[i]=min(dist[i][1]+dist[1][n], dist[i][n]+dist[n][1]);
        for (int j=2; j<n; j++)
            ans[i]=min(ans[i], dist[i][j]+rdist[1][j]+rdist[n][j]-1);
    }
    if (ans[val]<5e7)
        cout << ans[val];
    else
        cout << -1;
}

• Subtask 1: 0 / 6
• Subtask 2: 16 / 16
• Subtask 3: 24 / 24
• Subtask 4: 0 / 8
• Subtask 5: 0 / 46