// 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, 1LL);
} 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] + 1LL);
}
}
}
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 = 1e18 + 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 |
47488 KB |
Output is correct |
| 2 |
Correct |
30 ms |
47360 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
30 ms |
47480 KB |
Output is correct |
| 2 |
Correct |
34 ms |
47480 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
659 ms |
172664 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
30 ms |
47360 KB |
Output is correct |
| 2 |
Runtime error |
615 ms |
262144 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
680 ms |
262144 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
734 ms |
109980 KB |
Output is correct |
| 2 |
Correct |
531 ms |
93560 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
587 ms |
118588 KB |
Output is correct |
| 2 |
Correct |
172 ms |
54264 KB |
Output is correct |
| 3 |
Runtime error |
667 ms |
262148 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
161 ms |
54392 KB |
Output is correct |
| 2 |
Correct |
697 ms |
111224 KB |
Output is correct |
| 3 |
Correct |
622 ms |
81656 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
634 ms |
108732 KB |
Output is correct |
| 2 |
Correct |
742 ms |
109096 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
739 ms |
111480 KB |
Output is correct |
| 2 |
Correct |
624 ms |
81760 KB |
Output is correct |
