#include <bits/stdc++.h>
using namespace std;
#define for_(i, s, e) for (int i = s; i < (int) e; i++)
#define for__(i, s, e) for (ll i = s; i < e; i++)
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
#define endl '\n'
const int MXN = 1e6;
const ll INF = 1e17;
vi adj[MXN+1];
int chain[MXN+1], val[MXN+1], n;
pair<ll, ll> ans = {INF, 1};
void update(ll nu, ll de) {
ll g = __gcd(nu, de);
pair<ll, ll> temp = {nu/g, de/g};
if (ans.first == INF) ans = temp;
else if (temp.first*ans.second < ans.first*temp.second) ans = temp;
}
void dfs(int p, int parent) {
stack<ii> s, ss;
s.push({p, parent}); ss.push({p, parent});
while (s.size()) {
p = s.top().first, parent = s.top().second; s.pop();
for (int i: adj[p]) if (i != parent) {
s.push({i, p});
ss.push({i, p});
}
}
while (ss.size()) {
p = ss.top().first, parent = ss.top().second; ss.pop();
for (int i: adj[p]) if (i != parent) {
chain[p] = max(chain[p], chain[i]);
}
if (val[p] == 1) chain[p] += 1;
else chain[p] = 0;
}
}
void dfs2(int p, int parent, int pval) {
stack<vi> s;
s.push({p, parent, pval});
while (s.size()) {
p = s.top()[0], parent = s.top()[1], pval = s.top()[2]; s.pop();
vi mx(2);
for (int i: adj[p]) if (i != parent) {
if (chain[i] >= mx[0]) mx = {chain[i], mx[0]};
else mx[1] = max(mx[1], chain[i]);
}
update(val[p], mx[0]+mx[1]+1);
for (auto i: adj[p]) if (i != parent) s.push({i, p, val[p] == 1 ? max(pval, mx[0] == chain[i] ? mx[1] : mx[0])+1 : 0});
}
}
int main() {
#ifdef shiven
freopen("test.in", "r", stdin);
#endif
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n;
for_(i, 0, n-1) {
int a, b; cin >> a >> b;
a -= 1; b -= 1;
adj[a].push_back(b); adj[b].push_back(a);
}
for_(i, 0, n) cin >> val[i];
dfs(0, 0);
dfs2(0, 0, 0);
cout << ans.first << "/" << ans.second << endl;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23936 KB |
Output is correct |
2 |
Correct |
17 ms |
23808 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
18 ms |
23936 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
464 ms |
58712 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
17 ms |
23808 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
517 ms |
66456 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
531 ms |
67336 KB |
Output is correct |
2 |
Correct |
399 ms |
55548 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
548 ms |
82168 KB |
Output is correct |
2 |
Correct |
109 ms |
28664 KB |
Output is correct |
3 |
Incorrect |
527 ms |
67444 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
105 ms |
28664 KB |
Output is correct |
2 |
Correct |
520 ms |
67000 KB |
Output is correct |
3 |
Correct |
493 ms |
46584 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
489 ms |
65212 KB |
Output is correct |
2 |
Correct |
540 ms |
66612 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
531 ms |
67476 KB |
Output is correct |
2 |
Correct |
487 ms |
46512 KB |
Output is correct |