백준 24445번 알고리즘 수업 - 너비 우선 탐색 2 C++

https://www.acmicpc.net/problem/24445

24445번: 알고리즘 수업 - 너비 우선 탐색 2

 

bfs, 내림차순으로 방문

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <limits.h>

using namespace std;
using int64 = long long; 

int n, m, r;
int cnt = 1;
vector<int> ans;
vector<bool> found;
vector<vector<int>> board;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> n >> m >> r;
    ans = vector<int>(n + 1, 0);
    found = vector<bool>(n + 1, false);
    board = vector<vector<int>>(n + 1, vector<int>());

    for (int i = 0; i < m; i++) {
        int s, e;
        cin >> s >> e;
        board[s].push_back(e);
        board[e].push_back(s);
    }
    for (int i = 1; i <= n; i++) {
        sort(board[i].begin(), board[i].end(), greater<>());
    }
    queue<int> q;
    q.push(r);
    found[r] = true;
    while (!q.empty()) {
        int curr = q.front();
        ans[curr] = cnt++;
        q.pop();
        for (auto next : board[curr]) {
            if (found[next]) continue;
            q.push(next);
            found[next] = true;
        }
    }
    for (int i = 1; i <= n; i++) {
        cout << ans[i] << "\n";
    }
}