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Submission #745692

# Submission time Handle Problem Language Result Execution time Memory
745692 2023-05-21T02:36:03 Z rahulverma Network (BOI15_net) Java 11
0 / 100
 161 ms 12256 KB 
import java.io.*;
import java.util.*;

public class net {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int n = s.nextInt();
		ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
		for(int i = 0; i < n; i++) graph.add(new ArrayList<Integer>());
		for(int i = 1; i < n; i++) {
			int v1 = s.nextInt() - 1;
			int v2 = s.nextInt() - 1;
			graph.get(v1).add(v2);
			graph.get(v2).add(v1);
		}
		int root = 0;
		for(int i = 0; i < n; i++) {
			if(graph.get(i).size() != 1) {
				root = i;
			}
		}
		int[] dist = new int[n];
		Queue<Integer> q = new LinkedList<Integer>();
		Arrays.fill(dist, -1);
		q.add(root);
		dist[root] = 0;
		ArrayList<Integer> ans = new ArrayList<Integer>();
		ans.add(root);
		while(!q.isEmpty()) {
			int node = q.poll();
			for(int node2: graph.get(node)) {
				if(dist[node2] == -1) {
					dist[node2] = dist[node] + 1;
					q.add(node2);
					if(graph.get(node2).size() == 1) {
						ans.add(node2 + 1);
					}
				}
			}
		}
		/*for(int i = 0; i < n; i++) {
			System.out.println(dist[i]);
		}*/

		System.out.println(ans.size() / 2);
		for(int i = 0; i < ans.size(); i += 2) {
			System.out.println(ans.get(i) + " " + ans.get(i + 1));
		}
	}

}

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Runtime error 161 ms 12256 KB Execution failed because the return code was nonzero
2 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Runtime error 161 ms 12256 KB Execution failed because the return code was nonzero
2 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Runtime error 161 ms 12256 KB Execution failed because the return code was nonzero
2 Halted 0 ms 0 KB -