#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define long unsigned long
#define pb push_back
#define mp make_pair
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define lb lower_bound
#define ub upper_bound
#define sz(v) int((v).size())
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl '\n'
void solve() {
int n, m;
cin >> n >> m;
vector <vector <int>> graph(n+1);
vector <int> used(n+1), color(n+1, -1);
for (int i = 1; i <= m; i++) {
int a, b;
cin >> a >> b;
graph[a].pb(b);
graph[b].pb(a);
}
int flag = 0;
function<void(int, int, int)> dfs = [&](int v, int p, int c) {
used[v] = 1;
if (color[v] == -1) color[v] = c;
for (auto to : graph[v]) {
if (used[to]) {
if (used[to] == 1 && to != p) {
flag = 1;
}
continue;
}
dfs(to, v, 1-c);
}
used[v] = 2;
};
dfs(1, 1, 1);
if (flag) {
cout << "NO" << endl;
return;
}
//~ int forbidden, start, forbidden_leaves = 0;
//~ for (int i = 1; i <= n; i++) {
//~ if (sz(graph[i]) == 1) {
//~ start = graph[i][0];
//~ forbidden = color[i];
//~ break;
//~ }
//~ }
//~ for (int i = 1; i <= n; i++) {
//~ if (sz(graph[i]) == 1 && forbidden == color[i]) {
//~ forbidden_leaves++;
//~ }
//~ }
//~ set <int> visited;
//~ vector <int> order;
//~ int add = 1;
//~ function <void(int, int)> dfs2 = [&](int v, int p) {
//~ if (add) {
//~ visited.insert(v);
//~ order.pb(v);
//~ }
//~ if (sz(visited) == n-forbidden_leaves) {
//~ add = 0;
//~ }
//~ for (auto to : graph[v]) {
//~ if (to == p) continue;
//~ if (sz(graph[to]) == 1 && color[to] == forbidden) continue;
//~ dfs2(to, v);
//~ if (add) {
//~ visited.insert(v);
//~ order.pb(v);
//~ }
//~ }
//~ };
//~ dfs2(start, start);
cout << "YES" << endl;
cout << sz(order)*2 << endl;
for (auto to : order) cout << to << ' ';
for (auto to : order) cout << to << ' ';
}
int main() {
do_not_disturb
int t = 1;
//~ cin >> t;
while (t--) {
solve();
}
return 0;
}
Compilation message
newspapers.cpp: In function 'void solve()':
newspapers.cpp:87:16: error: 'order' was not declared in this scope
87 | cout << sz(order)*2 << endl;
| ^~~~~
newspapers.cpp:16:34: note: in definition of macro 'sz'
16 | #define sz(v) int((v).size())
| ^
