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Submission #244558

# Submission time Handle Problem Language Result Execution time Memory
244558 2020-07-04T09:40:36 Z oolimry Potemkin cycle (CEOI15_indcyc) C++14
20 / 100
 33 ms 2552 KB 
//HAPPY BIRTHDAY!!!
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> ii;

int depth[1005];
vector<int> adj[1005];
vector<int> paths[1005];
vector<ii> backs;
void dfs(int u){
	for(int v : adj[u]){
		if(depth[v] != 0){
			if(depth[v] < depth[u]-1){ ///back edge
				int dist = depth[u] - depth[v];
				backs.push_back(ii(dist, u));
			}
		}
		else{
			depth[v] = depth[u] + 1;
			paths[v].push_back(u);
			dfs(v);
		}
	}
}

signed main(){
	ios_base::sync_with_stdio(false); cin.tie(0);
	
	int n, m; cin >> n >> m;
	
	for(int i = 0;i < m;i++){
		int a, b; cin >> a >> b;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
	
	for(int i = 1;i <= n;i++){
		if(depth[i] != 0) continue; ///visited;
		backs.clear();
		
		depth[i] = 1;
		dfs(i);
		
		sort(backs.begin(), backs.end());
		for(ii e : backs){
			//cout << e.first << " " << e.second << ":" << endl;
			int u = e.second;
			int targetDepth = depth[u] - e.first;
			//cout << targetDepth << "\n";
			
			vector<int> P;
			while(depth[u] != targetDepth){
				P.push_back(u);
				
				for(int i = (int) (paths[u].size()-1);i >= 0;i--){
					int v = paths[u][i];
					//cout << u << " " << v << endl;
					
					if(depth[v] >= targetDepth){
						u = v;
						break;
					}
				}
			}
			
			P.push_back(u);
			
			if((int) P.size() >= 3){
				for(int x : P) cout << x << " ";
				return 0;
			}
			else{
				paths[e.second].push_back(u);
			}
		
		}
	}
	
	cout << "no";
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Incorrect 4 ms 384 KB Wrong answer on graph without induced cycle
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Too short sequence

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Too short sequence
2 Incorrect 5 ms 384 KB Wrong answer on graph without induced cycle

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Too short sequence
2 Incorrect 5 ms 384 KB Wrong answer on graph without induced cycle

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 512 KB Wrong answer on graph without induced cycle
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 512 KB Too short sequence
2 Incorrect 7 ms 512 KB Wrong answer on graph without induced cycle

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 1584 KB Too short sequence
2 Correct 12 ms 1152 KB Too short sequence
3 Incorrect 18 ms 1664 KB Wrong answer on graph without induced cycle
4 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 1028 KB Too short sequence
2 Incorrect 10 ms 1024 KB Wrong answer on graph without induced cycle

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 2552 KB Too short sequence
2 Incorrect 32 ms 2552 KB Wrong answer on graph without induced cycle
3 Halted 0 ms 0 KB -