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Submission #749848

# Submission time Handle Problem Language Result Execution time Memory
749848 2023-05-28T18:15:43 Z JellyTheOctopus Network (BOI15_net) C++17
0 / 100
 7 ms 11988 KB 
#include <bits/stdc++.h>
using namespace std;

int N;
vector<int> adjList[500001];
vector<int> leafNodes;

void DFS(int node, int parent) {
	int numVertices = 0;
	for (auto child: adjList[node]) {
		numVertices++;
		if (child != parent) {
			DFS(child, node);
		}
	}
	if (numVertices == 1) {
		leafNodes.push_back(node);
	}
}

int main() {
	cin >> N;
	for (int i = 0; i < N-1; i++) {
		int u, v;
		cin >> u >> v;
		adjList[u].push_back(v);
		adjList[v].push_back(u);
	}
	DFS(1, -1);
	int M = (int)leafNodes.size();
	cout << (M/2)+(M%2) << "\n";
	for (int i = 0; i < M; i += 2) {
		cout << leafNodes[(i+1)%M] << " " << leafNodes[(i+2)%M] << "\n";
	}
}

Subtask #1
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Incorrect 6 ms 11988 KB Breaking single line is causing network to disconnect.
9 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Incorrect 6 ms 11988 KB Breaking single line is causing network to disconnect.
9 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Correct 6 ms 11988 KB Output is correct
3 Correct 6 ms 11988 KB Output is correct
4 Correct 6 ms 11988 KB Output is correct
5 Correct 6 ms 11988 KB Output is correct
6 Correct 7 ms 11988 KB Output is correct
7 Correct 6 ms 11988 KB Output is correct
8 Incorrect 6 ms 11988 KB Breaking single line is causing network to disconnect.
9 Halted 0 ms 0 KB -