Submission #1257677

#	Time	Username	Problem	Language	Result	Execution time	Memory
1257677		Zbyszek99	Potemkin cycle (CEOI15_indcyc)	C++20	100 / 100	207 ms	114908 KiB

indcyc

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

int edge[1001][1001];
vi graph[1001];
vi graph2[1003001];
int color[1003001];
vi cycle;
vi path;
bool in_cycle[1001];

void dfs(int v)
{
    color[v] = 1;
    path.pb(v);
    forall(it,graph2[v])
    {
        if(color[it] == 0)
        {
            dfs(it);
            if(siz(cycle) != 0) return;
        }
        else if(color[it] == 1)
        {
            while(path.back() != it)
            {
                cycle.pb(path.back());
                path.pop_back();
            }
            cycle.pb(it);
            reverse(all(cycle));
            return;
        }
    }
    path.pop_back();
    color[v] = 2;
}


int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n,m;
    cin >> n >> m;
    rep(i,m)
    {
        int a,b;
        cin >> a >> b;
        if(a == b) continue;
        edge[a][b] = 1;
        edge[b][a] = 1;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    rep2(i,1,n)
    {
        forall(it,graph[i])
        {
            forall(it2,graph[i])
            {
                if(edge[it2][it] == 0 && it != it2)
                {
                    int p1 = it+i*(n+1);
                    int p2 = i+it2*(n+1);
                    graph2[p1].pb(p2);
                }
            }
        }
    }
    rep(i,n*(n+2))
    {
        if(color[i] == 0 && siz(cycle) == 0)
        {
            dfs(i);
        }
    }
    if(siz(cycle) == 0) cout << "no\n";
    vi c;
    forall(it,cycle)
    {
        c.pb(it%(n+1));
    }
    cycle = c;
    rep(i,siz(c))
    {
        int it = c[i];
        in_cycle[it] = 1;
        forall(it2,graph[it])
        {
            if(in_cycle[it2] && i != 0 && it2 != c[i-1])
            {
                vi ans;
                for(int j = i; j >= 0; j--)
                {
                    ans.pb(c[j]);
                    if(c[j] == it2) break;
                }
                forall(it,ans) cout << it << " ";
                return 0;
            }
        }   
    }
    forall(it,c) cout << it << " ";
}

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