#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 1e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
vector<ll> adj[N];
vector<ll> mx_depth(N);
vector<ll> par(N);
vector<ll> nxt(N);
bool ok = true;
void dfs1(ll u, ll p){
mx_depth[u] = 0;
nxt[u] = -1;
par[u] = p;
trav(v,adj[u]){
if(v == p) conts;
dfs1(v,u);
amax(mx_depth[u],mx_depth[v]+1);
}
vector<ll> big;
trav(v,adj[u]){
if(v == p) conts;
if(mx_depth[v] > 1){
big.pb(v);
}
}
if(sz(big) > 1){
ok = false;
}
else{
if(sz(big) == 1){
nxt[u] = big[0];
}
}
}
vector<ll> curr_ans;
void dfs2(ll u, ll p){
curr_ans.pb(u);
curr_ans.pb(u);
trav(v,adj[u]){
if(v == p) conts;
if(v != nxt[u]){
curr_ans.pb(u);
curr_ans.pb(v);
}
}
if(nxt[u] == -1) return;
ll v = nxt[u];
pll best = {-inf2,-inf2};
curr_ans.pb(u);
curr_ans.pb(v);
trav(w,adj[v]){
if(w == u) conts;
curr_ans.pb(w);
curr_ans.pb(v);
pll px = {mx_depth[w],w};
amax(best,px);
}
assert(best.ss != -inf2);
dfs2(best.ss,v);
}
void solve(int test_case)
{
ll n,m; cin >> n >> m;
rep1(i,m){
ll u,v; cin >> u >> v;
adj[u].pb(v), adj[v].pb(u);
}
if(m != n-1){
no;
return;
}
if(n == 1){
yes;
cout << 1 << endl << 1 << endl;
return;
}
rep1(i,n){
ok = true;
dfs1(i,-1);
if(ok){
yes;
dfs2(1,-1);
curr_ans.pb(1);
dfs2(1,-1);
auto ans = curr_ans;
assert(sz(ans) <= 5*n);
cout << sz(ans) << endl;
trav(x,ans) cout << x << " ";
cout << endl;
return;
}
}
no;
// yes;
// vector<ll> ans;
// for(int i = 2; i <= n; ++i){
// ans.pb(i);
// }
// if(!((n-1)&1)){
// ans.pb(1);
// }
// for(int i = 2; i <= n; ++i){
// ans.pb(i);
// }
// cout << sz(ans) << endl;
// trav(x,ans) cout << x << " ";
// cout << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Partially correct |
0 ms |
348 KB |
Provide a successful but not optimal strategy. |
3 |
Partially correct |
0 ms |
348 KB |
Provide a successful but not optimal strategy. |
4 |
Runtime error |
1 ms |
604 KB |
Execution killed with signal 6 |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Partially correct |
0 ms |
348 KB |
Provide a successful but not optimal strategy. |
3 |
Partially correct |
0 ms |
600 KB |
Provide a successful but not optimal strategy. |
4 |
Runtime error |
1 ms |
604 KB |
Execution killed with signal 6 |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Partially correct |
0 ms |
348 KB |
Provide a successful but not optimal strategy. |
3 |
Partially correct |
0 ms |
348 KB |
Provide a successful but not optimal strategy. |
4 |
Runtime error |
1 ms |
604 KB |
Execution killed with signal 6 |
5 |
Halted |
0 ms |
0 KB |
- |