Submission #1221797

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

using VI = vector<int>;
using VVI = vector<VI>;
using PII = pair<int, int>;
using LL = long long;
using VL = vector<LL>;
using VVL = vector<VL>;
using PLL = pair<LL, LL>;
using VS = vector<string>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second
template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}
template<class S, class T>
ostream& operator<<(ostream& os, const pair<S,T>& p){
  return os << p.FF << " " << p.SS;
}
template<class T>
void maxi(T& x, T y){
  if(x < y) x = y;
}
template<class T>
void mini(T& x, T y){
  if(x > y) x = y;
}


const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;

void dfs(int u, vector<bool>& used, VI& path, VVI& G){
  used[u] = true;
  for(int to: G[u]){
	if(used[to]) continue;
	path.PB(to);
	dfs(to, used, path, G);
	return;
  }
}

int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  int N, M; cin >> N >> M;
  VVI G(N+1);
  REP(i,M){
	int u, v; cin >> u >> v;
	G[u].PB(v);
	G[v].PB(u);
  }
  
  vector<bool> used(N+1, false);

  VI p1, p2;
  used[1] = true;
  dfs(1, used, p1, G);
  dfs(1, used, p2, G);
  reverse(ALL(p2));
  p2.PB(1);

  cout << (SZ(p1) + SZ(p2)) << endl;
  bool sp = false;
  for(auto i: p2){
	cout << (sp?" ":"") << i;
	sp = true;
  }
  for(auto i: p1){
	cout << (sp?" ":"") << i;
	sp = true;
  }
  cout << endl;
  
  return 0;
}

Submission Info

Judge Result