Submission #527097

#	Time	Username	Problem	Language	Result	Execution time	Memory
527097		maomao90	Potemkin cycle (CEOI15_indcyc)	C++17	50 / 100	1086 ms	6340 KiB

indcyc

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

#define REP(i, j, k) for (int i = j; i < k; i++)
#define RREP(i, j, k) for (int i = j; i >= k; i--)

template<class T>
inline bool mxto(T &a, T b) {return a < b ? a = b, 1 : 0;}
template<class T>
inline bool mnto(T &a, T b) {return a > b ? a = b, 1 : 0;}

typedef long long ll;
#define FI first
#define SE second
#define MP make_pair
typedef pair<int, int> ii;
#define pb push_back
#define ALL(x) x.begin(), x.end()
typedef vector<int> vi;
typedef vector<ii> vii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

#define MAXN 1005
#define INF 1000000005
#define LINF 1000000000000000005ll

int n, r;
vi adj[MAXN];
int vis[MAXN], dist[MAXN], p[MAXN];

int main() {
#ifndef DEBUG
	ios::sync_with_stdio(0), cin.tie(0);
#endif
	cin >> n >> r;
	REP (i, 0, r) {
		int a, b; cin >> a >> b;
		adj[a].pb(b);
		adj[b].pb(a);
	}
	REP (i, 1, n + 1) {
		set<ii> ban;
		queue<int> bfs;
		vis[i] = i;
		dist[i] = 0;
		bfs.push(i);
		cerr << i << '\n';
		while (!bfs.empty()) {
			int u = bfs.front(); bfs.pop();
			cerr << ' ' << u << '\n';
			for (int v : adj[u]) {
				cerr << "  " << v << '\n';
				if (vis[v] == i) {
					if (v == p[u]) continue;
					if (dist[u] == 1 && dist[v] == 1) {
						ban.insert(MP(min(u, v), max(u, v)));
						continue;
					}
					assert(dist[u] + dist[v] + 1 > 3);
					vi ans;
					int x = v;
					int a1 = -1;
					while (x != i) {
						a1 = x;
						ans.pb(x);
						x = p[x];
					}
					ans.pb(i);
					reverse(ALL(ans));
					x = u;
					int a2 = -1;
					while (x != i) {
						a2 = x;
						ans.pb(x);
						x = p[x];
					}
					if (ban.find(MP(min(a1, a2), max(a1, a2))) != ban.end()) {
						continue;
					}
					if (a1 == a2) {
						continue;
					}
					for (int a : ans) {
						cout << a << ' ';
					}
					cout << '\n';
					return 0;
				}
				vis[v] = i;
				dist[v] = dist[u] + 1;
				p[v] = u;
				bfs.push(v);
			}
		}
	}
	cout << "no\n";
	return 0;
}

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