#include <bits/stdc++.h>
int main() {
int N, M;
std::cin >> N >> M;
if (M != N - 1) {
std::cout << "NO" << std::endl;
return 0;
}
std::vector<int> A(M), B(M);
std::vector<int> deg(N);
std::vector<std::vector<int>> tree(N);
for (int i = 0; i < M; ++i) {
std::cin >> A[i] >> B[i];
--A[i], --B[i];
tree[A[i]].push_back(B[i]);
tree[B[i]].push_back(A[i]);
++deg[A[i]];
++deg[B[i]];
}
std::vector<int> sDeg(N);
for (int i = 0; i < N; ++i) {
for (const int t : tree[i]) {
if (deg[t] >= 2) {
++sDeg[i];
}
}
}
std::vector<bool> color(N);
auto dfs = [&](auto &&self, const int v, const int p, const bool c) -> void {
color[v] = c;
for (const int t : tree[v]) {
if (t == p) {
continue;
}
self(self, t, v, not c);
}
};
dfs(dfs, 0, -1, false);
bool okA = false, okB = false;
bool prmA = true, prmB = true;
for (int i = 0; i < N; ++i) {
if (color[i] == false and deg[i] >= 3) {
prmA = false;
}
if (color[i] == false and deg[i] == 1) {
okA = true;
}
if (color[i] == true and deg[i] >= 3) {
prmB = false;
}
if (color[i] == true and deg[i] == 1) {
okB = true;
}
}
prmA &= okA;
prmB &= okB;
if ((not prmA) and (not prmB)) {
std::cout << "NO" << std::endl;
return 0;
}
std::cout << "YES" << std::endl;
std::vector<int> answer;
for (int i = 1; i <= N; ++i) {
answer.push_back(i);
}
if (N != N / 2 * 2) {
answer.push_back(N);
}
for (int i = N / 2 * 2; i >= 1; --i) {
answer.push_back(i);
}
std::cout << answer.size() << std::endl;
for (auto &e : answer) {
std::cout << e << ' ';
}
std::cout << std::endl;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
