#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> n >> m;
vector<vector<int>> adj(n);
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
u--;
v--;
adj[u].push_back(v);
adj[v].push_back(u);
}
if (m != n - 1) {
cout << "NO\n";
return 0;
}
int cnt3 = 0;
int cnt2 = 0;
for (int u = 0; u < n; u++) {
if (adj[u].size() >= 3) {
cnt3++;
}
if (adj[u].size() == 2) {
cnt2++;
}
}
if (cnt3 == 0) {
cout << "YES\n";
} else {
if (cnt3 >= 2) {
cout << "NO\n";
return 0;
}
if (cnt2 >= 2) {
cout << "NO\n";
return 0;
} else {
cout << "YES\n";
return 0;
}
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |