Submission #24868517

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Source Code Expand

#include <bits/stdc++.h>
/*#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("tune=native")*/
using namespace std;
typedef long long ll;
typedef long double ld;

const int MAX_N = 200005;

int n;
vector<int> g[MAX_N];
vector<int> order;

void dfs(int u, int p = -1)
{
	order.push_back(u);
	for (int v : g[u])
		if (v != p)
		{
			dfs(v, u);
			order.push_back(u);
		}
}

int32_t main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin >> n;
	for (int i = 0; i < n - 1; i++)
	{
		int a, b;
		cin >> a >> b;
		a--; b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}

	for (int i = 0; i < n; i++)
		sort(g[i].begin(), g[i].end());

	dfs(0);

	for (int x : order)
		cout << (x + 1) << ' ';
	cout << '\n';

	return 0;
}

Submission Info

Judge Result