// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h>
using namespace std;
#define REP(i, s, e) for (int i = (s); i < (e); i++)
#define RREP(i, s, e) for (int i = (s); i >= (e); i--)
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define SZ(_a) (int) _a.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;
#ifndef DEBUG
#define cerr if (0) cerr
#endif
const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 1500005;
const int MOD = 1000000007;
int n, k;
vi adj[MAXN];
bool bad[MAXN];
int d[MAXN], mxd[MAXN], smxd[MAXN];
bool pos;
bool dfs(int u, int p) {
mxd[u] = d[u];
smxd[u] = 0;
bool res = d[u] % k == 0;
int cnt = 0;
int mx = -INF, smx = -INF, cmx = -INF, csmx = -INF;
for (int v : adj[u]) {
if (v == p || bad[v]) {
continue;
}
d[v] = d[u] + 1;
bool tmp = dfs(v, u);
/*
if (!pos) {
return 0;
}
*/
res |= tmp;
cnt += tmp;
if (mxd[v] >= mxd[u]) {
smxd[u] = max(mxd[u], smxd[v]);
mxd[u] = mxd[v];
} else {
mxto(smxd[u], mxd[v]);
}
int x = mxd[v] - d[u];
if (tmp) {
x = k - d[u] % k - 1;
}
if (x >= mx) {
smx = mx;
mx = x;
} else {
mxto(smx, x);
}
if (tmp) {
if (mxd[v] >= cmx) {
csmx = cmx;
cmx = mxd[v];
} else {
mxto(csmx, mxd[v]);
}
}
}
if (cnt >= 2 && 2 * d[u] % k != 0 && cmx + csmx - 2 * d[u] + 1 >= k) {
pos = 0;
//return 0;
}
if (d[u] % k != 0 && mx + smx + 1 >= k) {
//pos = 0;
//return 0;
}
return res;
}
int main() {
#ifndef DEBUG
ios::sync_with_stdio(0), cin.tie(0);
#endif
cin >> n >> k;
REP (i, 1, n) {
int u, v; cin >> u >> v;
adj[u].pb(v);
adj[v].pb(u);
}
REP (i, 1, n + 1) {
d[i] = 0;
dfs(i, -1);
if (mxd[i] + smxd[i] + 1 < k) {
bad[i] = 1;
}
}
REP (i, 1, n + 1) {
if (bad[i]) {
continue;
}
d[i] = 0;
pos = 1;
dfs(i, -1);
if (pos) {
cerr << i << '\n';
cout << "YES\n";
cout << 0 << '\n';
return 0;
}
}
cout << "NO\n";
cout << 0 << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Partially correct |
17 ms |
35540 KB |
Output is partially correct |
2 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
3 |
Partially correct |
19 ms |
35536 KB |
Output is partially correct |
4 |
Partially correct |
19 ms |
35524 KB |
Output is partially correct |
5 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
6 |
Partially correct |
19 ms |
35512 KB |
Output is partially correct |
7 |
Incorrect |
19 ms |
35576 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Partially correct |
17 ms |
35540 KB |
Output is partially correct |
2 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
3 |
Partially correct |
19 ms |
35536 KB |
Output is partially correct |
4 |
Partially correct |
19 ms |
35524 KB |
Output is partially correct |
5 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
6 |
Partially correct |
19 ms |
35512 KB |
Output is partially correct |
7 |
Incorrect |
19 ms |
35576 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Partially correct |
17 ms |
35540 KB |
Output is partially correct |
2 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
3 |
Partially correct |
19 ms |
35536 KB |
Output is partially correct |
4 |
Partially correct |
19 ms |
35524 KB |
Output is partially correct |
5 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
6 |
Partially correct |
19 ms |
35512 KB |
Output is partially correct |
7 |
Incorrect |
19 ms |
35576 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Partially correct |
17 ms |
35540 KB |
Output is partially correct |
2 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
3 |
Partially correct |
19 ms |
35536 KB |
Output is partially correct |
4 |
Partially correct |
19 ms |
35524 KB |
Output is partially correct |
5 |
Partially correct |
19 ms |
35540 KB |
Output is partially correct |
6 |
Partially correct |
19 ms |
35512 KB |
Output is partially correct |
7 |
Incorrect |
19 ms |
35576 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |