// g++ -std=c++14
/*
Today might be the chance to grasp the chance to let your talent bloom.
May be tomorrow, the day after, or next year...
May be even when you are 30. I'm not sure if physique has anything to do with it
but if you think that it will never come, it probably never will.
- Tooru Oikawa.
*/
#include<bits/stdc++.h>
typedef long long ll;
typedef long double lld;
using namespace std;
#define endl "\n"
#define fi first
#define se second
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define MEMS(a,b) memset(a,b,sizeof(a))
#define _ ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define __ freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define all(c) c.begin(),c.end()
#define pii pair<int, int>
#define tr(...) cout<<__FUNCTION__<<' '<<__LINE__<<" = ";trace(#__VA_ARGS__, __VA_ARGS__)
template<typename S, typename T>
ostream& operator<<(ostream& out,pair<S,T> const& p){out<<'('<<p.fi<<", "<<p.se<<')';return out;}
template<typename T>
ostream& operator<<(ostream& out,vector<T> const& v){
ll l=v.size();for(ll i=0;i<l-1;i++)out<<v[i]<<' ';if(l>0)out<<v[l-1];return out;}
template <typename T>
ostream &operator<<(ostream &out, set<T> const &v) {
for (auto i = v.begin(); i != v.end(); i++)
out << (*i) << ' ';
return out;
}
template <typename T, typename V>
ostream &operator<<(ostream &out, map<T, V> const &v) {
for (auto i = v.begin(); i != v.end(); i++)
out << "\n" << (i->first) << ":" << (i->second);
return out;
}
template<typename T>
void trace(const char* name, T&& arg1){cout<<name<<" : "<<arg1<<endl;}
template<typename T, typename... Args>
void trace(const char* names, T&& arg1, Args&&... args){
const char* comma = strchr(names + 1, ',');cout.write(names, comma-names)<<" : "<<arg1<<" | ";trace(comma+1,args...);}
// #define int ll
const int N = 2e6 + 100;
int n;
vector<vector<int>> g(N);
int arr[N];
int dp_down[N], dp_up[N];
int parent[N];
int ans0 = 0;
void dfs0(int v, int p) {
parent[v] = p;
int curr = (arr[v] == 1);
vector<int> child;
for (auto u : g[v]) {
if (u == p) continue;
dfs0(u, v);
curr = max(curr, dp_down[u] + 1);
child.push_back(dp_down[u]);
}
if (arr[v] == 1) {
dp_down[v] = curr;
if (child.empty()) {
ans0 = max(ans0, 1);
} else if ((int)child.size() == 1) {
ans0 = max(ans0, child.back() + 1);
} else {
sort(all(child));
reverse(all(child));
ans0 = max(ans0, child[0] + child[1] + 1);
}
}
}
void dfs1(int v, int p, int mx_len = 0) {
// tr(v, mx_len);
dp_up[v] = mx_len;
if (arr[v] == 1) {
multiset<int> child;
child.insert(mx_len);
for (auto u : g[v]) {
if (u == p) continue;
child.insert(dp_down[u]);
}
for (auto u : g[v]) {
if (u == p) continue;
auto itr = child.find(dp_down[u]);
if (itr == child.end()) {
cout << "hahah" << endl;
} else {
child.erase(child.find(dp_down[u]));
int heremx = *child.rbegin() + 1;
dfs1(u, v, heremx);
child.insert(dp_down[u]);
}
}
} else {
for (auto u : g[v]) {
if (u == p) continue;
dfs1(u, v, 0);
}
}
}
int cmp(int a, int b, int c, int d) {
return (a * d < c * b);
}
const int inf = 1e9 + 1;
int solve() {
cin >> n;
for (int i = 0; i < n - 1; i++) {
int v, u;
cin >> v >> u;
g[u].push_back(v);
g[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
cin >> arr[i];
}
dfs0(1, 0);
dfs1(1, 0);
if (ans0 == 0) {
int mi = inf;
for (int i = 1; i <= n; i++) {
mi = min(mi, arr[i]);
}
cout << mi << "/1" << endl;
} else {
int a = 1, b = ans0;
for (int i = 1; i <= n; i++) {
vector<int> pth;
for (auto j : g[i]) {
if (j == parent[i]) continue;
pth.push_back(dp_down[j]);
}
pth.push_back(dp_up[i]);
sort(all(pth));
reverse(all(pth));
// tr(i, pth, a, b);
if ((int)pth.size() == 1) {
int c = arr[i], d = pth[0] + 1;
if (!cmp(a, b, c, d)) {
a = c, b = d;
}
} else {
int c = arr[i], d = 1 + pth[0] + pth[1];
if (!cmp(a, b, c, d)) {
a = c, b = d;
}
}
}
assert(b != 0 && a != 0);
int g = __gcd(a, b);
a /= g;
b /= g;
cout << a << "/" << b << endl;
}
return 0;
}
int32_t main(){ _
int t;
// cin >> t;
t = 1;
while (t--) solve();
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
31 ms |
47360 KB |
Output is correct |
| 2 |
Correct |
31 ms |
47352 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
30 ms |
47480 KB |
Output is correct |
| 2 |
Correct |
30 ms |
47360 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
687 ms |
160156 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
30 ms |
47356 KB |
Output is correct |
| 2 |
Correct |
827 ms |
256928 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
698 ms |
262148 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
727 ms |
94140 KB |
Output is correct |
| 2 |
Correct |
530 ms |
82168 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
630 ms |
98668 KB |
Output is correct |
| 2 |
Correct |
136 ms |
52112 KB |
Output is correct |
| 3 |
Runtime error |
723 ms |
262148 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
133 ms |
52088 KB |
Output is correct |
| 2 |
Correct |
735 ms |
95736 KB |
Output is correct |
| 3 |
Correct |
602 ms |
71488 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
666 ms |
93420 KB |
Output is correct |
| 2 |
Correct |
708 ms |
93588 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
763 ms |
95684 KB |
Output is correct |
| 2 |
Correct |
585 ms |
71416 KB |
Output is correct |
