백준 알고리즘 24480번 : 알고리즘 수업 - 깊이 우선 탐색 2

링크

https://www.acmicpc.net/problem/24480

sol1) DFS

#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/rope>
#define fastio ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
using namespace std;
using namespace __gnu_cxx;

#define X first
#define Y second
#define int int64_t
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define Compress(v) sort(all(v)), (v).erase(unique(all(v)), (v).end())
#define OOB(x, y) ((x) < 0 || (x) >= n || (y) < 0 || (y) >= m)
#define IDX(v, x) (lower_bound(all(v), x) - (v).begin())
#define debug(x) cout << (#x) << ": " << (x) << '\n'

using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using tii = tuple<int, int, int>;
template <typename T>
using wector = vector<vector<T>>;

vector<int> adj[100001];
vector<int> dist(100'001, 0);
int idx = 1, n, m, r;
void dfs(int cur)
{
    dist[cur] = idx++;
    for (auto &nxt : adj[cur])
    {
        if (dist[nxt] != 0)
            continue;
        dfs(nxt);
    }
}

int32_t main()
{
    fastio;
    cin >> n >> m >> r;
    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++)
        sort(all(adj[i]), greater<>());
    dfs(r);
    for (int i = 1; i <= n; i++)
        cout << dist[i] << "\n";
}

정렬을 내림차순으로 해주면 됩니다.