Submission #1259653

#	Time	Username	Problem	Language	Result	Execution time	Memory
1259653		nqknht	Potemkin cycle (CEOI15_indcyc)	C++20	50 / 100	1102 ms	121584 KiB

indcyc

#include <bits/stdc++.h>

#define ll long long
#define fi first
#define se second
#define len(s) (ll) s.size()
#define LS(x) (1 << x)

const ll I = 3e5 + 9;
const ll Z = 1e9 + 7;

using namespace std;

int u[I], v[I], n, m;
vector<int> adj[1506];

namespace subfull
{
    int gen(int u, int v)
    {
        // if(u > v) swap(u, v);
        // cout << (u - 1) * n + v << "\n";
        return (u - 1) * n + v;
    }
    pair<int, int> decode(int x)
    {
        int u = x / n;
        int v = x % n;
        if (v == 0)
            v = n;
        else
            u++;
        return make_pair(u, v);
    }
    int id[1009][1009];
    int icycle = 0, vis[2000009];

    vector<ll> G[1000009];
    vector<vector<int>> adj;

    void dfs(int x)
    {
        if (icycle != 0)
            return;
        vis[x] = 1;
        for (auto z : adj[x])
        {
            if (vis[z] == 1)
            {
                icycle = z;
                return;
            }
            dfs(z);
            if (icycle == -1)
                return;
            if (icycle != 0)
            {
                int p = z / 2;
                if (z % 2 == 1)
                    cout << v[p] << " ";
                else
                    cout << u[p] << " ";
                if (z == icycle)
                    icycle = -1;
                return;
            }
        }
        vis[x] = 2;
    }

    void solve()
    {
        for (int i = 1; i <= m; i++)
        {
            id[u[i]][v[i]] = i * 2;
            id[v[i]][u[i]] = i * 2 + 1;
        }
        adj.resize(m * 2 + 2);
        for (int i = 1; i <= m; i++)
        {
            for (int w = 1; w <= n; w++)
            {
                if (id[v[i]][w] && !id[u[i]][w] && u[i] != w)
                    adj[i * 2].push_back(id[v[i]][w]);
                if (id[u[i]][w] && !id[v[i]][w] && v[i] != w)
                    adj[i * 2 + 1].push_back(id[u[i]][w]);
            }
        }
        memset(vis, 0, sizeof vis);
        for (int i = 2; i <= m * 2 + 1; i++)
        {
            if (vis[i] == 0)
                dfs(i);
            if (icycle > 0)
                if (i % 2 == 1)
                    cout << v[i / 2];
                else
                    cout << u[i / 2];
            if (icycle != 0)
                return;
        }
        cout << "no";
    }
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> m;
    for (int i = 1; i <= m; i++)
        cin >> u[i] >> v[i];
    subfull::solve();
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 0 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10