BFS

#include <iostream>
#include <vector>
#include <queue>

using namespace std;

const int MAX = 100;
vector<int> adj[MAX];
bool visited[MAX];

void BFS(int s) {
  queue<int> q;
  q.push(s);
  visited[s] = true;
  while (!q.empty()) {
    int u = q.front();
    q.pop();
    cout << u << " ";
    for (int i = 0; i < adj[u].size(); i++) {
      int v = adj[u][i];
      if (!visited[v]) {
        q.push(v);
        visited[v] = true;
      }
    }
  }
}

int main() {
  int n, m, s;
  cin >> n >> m >> s;
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  BFS(s);
  return 0;
}