#include <bits/stdc++.h>
using namespace std;
using ll = long long;
// #define VERIFY
const int MAXN = 1001;
vector<int> g[MAXN], ans;
int n, m, md = 0, f = 0, cnt = 0, sz[MAXN];
void dfs(int u, int p = -1, int d = 0) {
if (md < d) {
md = d;
f = u;
}
for (int v : g[u]) {
if (v != p) dfs(v, u, d+1);
}
}
void dfs2(int u, int p = -1) {
if (cnt != n && g[u].size() != 1) ans.emplace_back(u);
cnt++;
for (int v : g[u]) {
if (v != p) {
dfs2(v, u);
if (cnt != n && ans.back() != u) ans.emplace_back(u);
}
}
}
int dfs3(int u, int p = -1) {
sz[u] = 1;
for (int v : g[u]) {
if (v != p) sz[u] = max(sz[u], dfs3(v, u)+1);
}
sort(g[u].begin(), g[u].end(), [&](int a, int b){
return sz[a] < sz[b];
});
return sz[u];
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v; cin >> u >> v;
g[u].emplace_back(v);
g[v].emplace_back(u);
}
if (n - 1 != m) {
cout << "NO\n";
return 0;
}
bool ok = true;
for (int i = 1; i <= n; i++) {
int cnt = 0;
for (int u : g[i]) {
md = 0;
dfs(u, i);
cnt += md >= 2;
}
if (cnt >= 3) {
ok = false;
break;
}
}
cout << (ok ? "YES\n" : "NO\n");
if (n == 1) {
cout << "1\n1\n";
} else if (n == 2) {
cout << "2\n1 1\n";
} else if (ok) {
md = 0;
dfs(1);
dfs3(f);
dfs2(f);
vector<int> v;
for (int i : ans) v.emplace_back(i);
reverse(ans.begin(), ans.end());
for (int i : ans) v.emplace_back(i);
#ifdef VERIFY
assert(n <= 20);
int bits = (1<<n)-1;
for (int i : v) {
int nw = 0;
for (int j = 0; j < n; j++) {
if (i != j + 1 && bits & (1<<j)) {
for (int u : g[j+1]) {
nw |= 1<<(u-1);
}
}
}
bits = nw;
}
if (__popcount(bits) != 0) throw 1;
#endif
cout << v.size() << "\n";
for (int i : v) cout << i << " ";
cout << "\n";
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
344 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
344 KB |
Output is correct |
13 |
Correct |
1 ms |
344 KB |
Output is correct |
14 |
Correct |
1 ms |
344 KB |
Output is correct |
15 |
Correct |
1 ms |
344 KB |
Output is correct |
16 |
Correct |
0 ms |
344 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
1 ms |
348 KB |
Output is correct |
25 |
Correct |
1 ms |
348 KB |
Output is correct |
26 |
Correct |
1 ms |
604 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
0 ms |
348 KB |
Output is correct |
29 |
Correct |
0 ms |
600 KB |
Output is correct |
30 |
Correct |
1 ms |
344 KB |
Output is correct |
31 |
Correct |
0 ms |
348 KB |
Output is correct |
32 |
Correct |
0 ms |
348 KB |
Output is correct |
33 |
Correct |
0 ms |
484 KB |
Output is correct |
34 |
Correct |
0 ms |
348 KB |
Output is correct |
35 |
Correct |
1 ms |
484 KB |
Output is correct |
36 |
Correct |
1 ms |
344 KB |
Output is correct |
37 |
Correct |
1 ms |
348 KB |
Output is correct |
38 |
Correct |
0 ms |
348 KB |
Output is correct |
39 |
Correct |
1 ms |
348 KB |
Output is correct |
40 |
Correct |
0 ms |
480 KB |
Output is correct |
41 |
Correct |
0 ms |
348 KB |
Output is correct |
42 |
Correct |
1 ms |
348 KB |
Output is correct |
43 |
Correct |
0 ms |
348 KB |
Output is correct |
44 |
Correct |
1 ms |
344 KB |
Output is correct |
45 |
Correct |
1 ms |
348 KB |
Output is correct |
46 |
Correct |
0 ms |
348 KB |
Output is correct |
47 |
Correct |
0 ms |
344 KB |
Output is correct |
48 |
Correct |
1 ms |
600 KB |
Output is correct |
49 |
Correct |
0 ms |
348 KB |
Output is correct |
50 |
Correct |
0 ms |
348 KB |
Output is correct |
51 |
Correct |
0 ms |
348 KB |
Output is correct |
52 |
Correct |
0 ms |
348 KB |
Output is correct |
53 |
Correct |
0 ms |
348 KB |
Output is correct |
54 |
Correct |
0 ms |
344 KB |
Output is correct |
55 |
Correct |
0 ms |
344 KB |
Output is correct |
56 |
Correct |
0 ms |
348 KB |
Output is correct |
57 |
Correct |
0 ms |
348 KB |
Output is correct |
58 |
Correct |
1 ms |
348 KB |
Output is correct |
59 |
Correct |
1 ms |
348 KB |
Output is correct |
60 |
Correct |
0 ms |
348 KB |
Output is correct |
61 |
Correct |
1 ms |
348 KB |
Output is correct |
62 |
Correct |
0 ms |
348 KB |
Output is correct |
63 |
Correct |
0 ms |
480 KB |
Output is correct |
64 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
352 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
7 ms |
604 KB |
Output is correct |
12 |
Correct |
3 ms |
600 KB |
Output is correct |
13 |
Correct |
4 ms |
344 KB |
Output is correct |
14 |
Correct |
4 ms |
352 KB |
Output is correct |
15 |
Correct |
4 ms |
348 KB |
Output is correct |
16 |
Correct |
8 ms |
604 KB |
Output is correct |
17 |
Correct |
8 ms |
608 KB |
Output is correct |
18 |
Correct |
8 ms |
604 KB |
Output is correct |
19 |
Correct |
9 ms |
548 KB |
Output is correct |
20 |
Correct |
8 ms |
600 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
344 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
344 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
344 KB |
Output is correct |
13 |
Correct |
1 ms |
344 KB |
Output is correct |
14 |
Correct |
1 ms |
344 KB |
Output is correct |
15 |
Correct |
1 ms |
344 KB |
Output is correct |
16 |
Correct |
0 ms |
344 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
0 ms |
348 KB |
Output is correct |
21 |
Correct |
0 ms |
348 KB |
Output is correct |
22 |
Correct |
0 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
1 ms |
348 KB |
Output is correct |
25 |
Correct |
1 ms |
348 KB |
Output is correct |
26 |
Correct |
1 ms |
604 KB |
Output is correct |
27 |
Correct |
0 ms |
348 KB |
Output is correct |
28 |
Correct |
0 ms |
348 KB |
Output is correct |
29 |
Correct |
0 ms |
600 KB |
Output is correct |
30 |
Correct |
1 ms |
344 KB |
Output is correct |
31 |
Correct |
0 ms |
348 KB |
Output is correct |
32 |
Correct |
0 ms |
348 KB |
Output is correct |
33 |
Correct |
0 ms |
484 KB |
Output is correct |
34 |
Correct |
0 ms |
348 KB |
Output is correct |
35 |
Correct |
1 ms |
484 KB |
Output is correct |
36 |
Correct |
1 ms |
344 KB |
Output is correct |
37 |
Correct |
1 ms |
348 KB |
Output is correct |
38 |
Correct |
0 ms |
348 KB |
Output is correct |
39 |
Correct |
1 ms |
348 KB |
Output is correct |
40 |
Correct |
0 ms |
480 KB |
Output is correct |
41 |
Correct |
0 ms |
348 KB |
Output is correct |
42 |
Correct |
1 ms |
348 KB |
Output is correct |
43 |
Correct |
0 ms |
348 KB |
Output is correct |
44 |
Correct |
1 ms |
344 KB |
Output is correct |
45 |
Correct |
1 ms |
348 KB |
Output is correct |
46 |
Correct |
0 ms |
348 KB |
Output is correct |
47 |
Correct |
0 ms |
344 KB |
Output is correct |
48 |
Correct |
1 ms |
600 KB |
Output is correct |
49 |
Correct |
0 ms |
348 KB |
Output is correct |
50 |
Correct |
0 ms |
348 KB |
Output is correct |
51 |
Correct |
0 ms |
348 KB |
Output is correct |
52 |
Correct |
0 ms |
348 KB |
Output is correct |
53 |
Correct |
0 ms |
348 KB |
Output is correct |
54 |
Correct |
0 ms |
344 KB |
Output is correct |
55 |
Correct |
0 ms |
344 KB |
Output is correct |
56 |
Correct |
0 ms |
348 KB |
Output is correct |
57 |
Correct |
0 ms |
348 KB |
Output is correct |
58 |
Correct |
1 ms |
348 KB |
Output is correct |
59 |
Correct |
1 ms |
348 KB |
Output is correct |
60 |
Correct |
0 ms |
348 KB |
Output is correct |
61 |
Correct |
1 ms |
348 KB |
Output is correct |
62 |
Correct |
0 ms |
348 KB |
Output is correct |
63 |
Correct |
0 ms |
480 KB |
Output is correct |
64 |
Correct |
0 ms |
348 KB |
Output is correct |
65 |
Correct |
1 ms |
348 KB |
Output is correct |
66 |
Correct |
1 ms |
352 KB |
Output is correct |
67 |
Correct |
0 ms |
348 KB |
Output is correct |
68 |
Correct |
0 ms |
348 KB |
Output is correct |
69 |
Correct |
0 ms |
348 KB |
Output is correct |
70 |
Correct |
0 ms |
348 KB |
Output is correct |
71 |
Correct |
0 ms |
356 KB |
Output is correct |
72 |
Correct |
0 ms |
348 KB |
Output is correct |
73 |
Correct |
0 ms |
348 KB |
Output is correct |
74 |
Correct |
1 ms |
348 KB |
Output is correct |
75 |
Correct |
0 ms |
348 KB |
Output is correct |
76 |
Correct |
1 ms |
348 KB |
Output is correct |
77 |
Correct |
0 ms |
348 KB |
Output is correct |
78 |
Correct |
0 ms |
348 KB |
Output is correct |
79 |
Correct |
0 ms |
348 KB |
Output is correct |
80 |
Correct |
1 ms |
348 KB |
Output is correct |
81 |
Correct |
0 ms |
348 KB |
Output is correct |
82 |
Correct |
0 ms |
348 KB |
Output is correct |
83 |
Correct |
1 ms |
344 KB |
Output is correct |
84 |
Correct |
1 ms |
344 KB |
Output is correct |
85 |
Correct |
1 ms |
348 KB |
Output is correct |
86 |
Correct |
1 ms |
348 KB |
Output is correct |
87 |
Correct |
1 ms |
348 KB |
Output is correct |
88 |
Correct |
1 ms |
348 KB |
Output is correct |
89 |
Correct |
12 ms |
344 KB |
Output is correct |
90 |
Correct |
10 ms |
344 KB |
Output is correct |
91 |
Correct |
9 ms |
348 KB |
Output is correct |
92 |
Correct |
7 ms |
348 KB |
Output is correct |
93 |
Correct |
13 ms |
528 KB |
Output is correct |
94 |
Correct |
10 ms |
344 KB |
Output is correct |
95 |
Correct |
13 ms |
344 KB |
Output is correct |
96 |
Correct |
12 ms |
344 KB |
Output is correct |
97 |
Correct |
7 ms |
344 KB |
Output is correct |
98 |
Correct |
12 ms |
348 KB |
Output is correct |
99 |
Correct |
9 ms |
348 KB |
Output is correct |
100 |
Correct |
10 ms |
348 KB |
Output is correct |
101 |
Correct |
9 ms |
528 KB |
Output is correct |
102 |
Correct |
9 ms |
348 KB |
Output is correct |
103 |
Correct |
12 ms |
348 KB |
Output is correct |
104 |
Correct |
7 ms |
348 KB |
Output is correct |
105 |
Correct |
8 ms |
564 KB |
Output is correct |
106 |
Correct |
10 ms |
348 KB |
Output is correct |
107 |
Correct |
8 ms |
348 KB |
Output is correct |
108 |
Correct |
12 ms |
600 KB |
Output is correct |
109 |
Correct |
10 ms |
344 KB |
Output is correct |
110 |
Correct |
9 ms |
348 KB |
Output is correct |
111 |
Correct |
8 ms |
348 KB |
Output is correct |
112 |
Correct |
8 ms |
348 KB |
Output is correct |
113 |
Correct |
13 ms |
348 KB |
Output is correct |
114 |
Correct |
11 ms |
344 KB |
Output is correct |
115 |
Correct |
8 ms |
344 KB |
Output is correct |
116 |
Correct |
10 ms |
348 KB |
Output is correct |
117 |
Correct |
12 ms |
348 KB |
Output is correct |
118 |
Correct |
11 ms |
528 KB |
Output is correct |
119 |
Correct |
9 ms |
348 KB |
Output is correct |
120 |
Correct |
11 ms |
344 KB |
Output is correct |
121 |
Correct |
11 ms |
348 KB |
Output is correct |
122 |
Correct |
8 ms |
528 KB |
Output is correct |
123 |
Correct |
8 ms |
348 KB |
Output is correct |
124 |
Correct |
12 ms |
344 KB |
Output is correct |
125 |
Correct |
7 ms |
344 KB |
Output is correct |
126 |
Correct |
7 ms |
492 KB |
Output is correct |
127 |
Correct |
7 ms |
348 KB |
Output is correct |
128 |
Correct |
12 ms |
348 KB |
Output is correct |
129 |
Correct |
1 ms |
348 KB |
Output is correct |
130 |
Correct |
1 ms |
348 KB |
Output is correct |
131 |
Correct |
1 ms |
348 KB |
Output is correct |
132 |
Correct |
1 ms |
484 KB |
Output is correct |
133 |
Correct |
1 ms |
348 KB |
Output is correct |
134 |
Correct |
10 ms |
2140 KB |
Output is correct |
135 |
Correct |
9 ms |
1884 KB |
Output is correct |
136 |
Correct |
24 ms |
5468 KB |
Output is correct |
137 |
Correct |
17 ms |
3416 KB |
Output is correct |
138 |
Correct |
26 ms |
4752 KB |
Output is correct |
139 |
Correct |
48 ms |
7876 KB |
Output is correct |
140 |
Correct |
7 ms |
1628 KB |
Output is correct |
141 |
Correct |
3 ms |
860 KB |
Output is correct |
142 |
Correct |
43 ms |
7536 KB |
Output is correct |
143 |
Correct |
51 ms |
8260 KB |
Output is correct |
144 |
Correct |
8 ms |
856 KB |
Output is correct |
145 |
Correct |
8 ms |
600 KB |
Output is correct |