// 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;
vector<int> child;
void dfs0(int v, int p) {
parent[v] = p;
int curr = (arr[v] == 1);
child.clear();
child.resize(2);
for (auto u : g[v]) {
if (u == p) continue;
dfs0(u, v);
curr = max(curr, dp_down[u] + 1);
int x = dp_down[u];
if (x > child[0]) {
child[1] = child[0];
child[0] = x;
} else if (x > child[1]) {
child[1] = x;
}
}
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 {
ans0 = max(ans0, child[0] + child[1] + 1);
}
}
}
void dfs1(int v, int p, int mx_len = 0) {
// tr(v, mx_len);
// if (v % 1000 == 0) {
// tr(v, g[v]);
// }
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;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r)
{
uniform_int_distribution<int> uid(l, r);
return uid(rng);
}
void gen() {
n = rand(1e5, 1e5);
vector<int> curr = {0};
vector<int> parent(n + 1);
for (int i = 1; i <= n; i++) {
int kk = curr.size();
// int p = curr[rand(0, kk - 1)];
int p = curr.back();
parent[i] = p;
curr.push_back(i);
if (i > 1) {
g[parent[i]].push_back(i);
g[i].push_back(parent[i]);
}
}
for (int i = 1; i <= n; i++) {
int temp = rand(1, 10);
if (temp > 5) {
arr[i] = rand(1, 1e9);
} else {
arr[i] = 1;
}
// arr[i] = rand(1, 1);
}
// tr(n);
cout << n << endl;
}
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];
}
// gen();
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();
}
Compilation message
mag.cpp: In function 'void gen()':
mag.cpp:155:13: warning: unused variable 'kk' [-Wunused-variable]
int kk = curr.size();
^~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
33 ms |
47360 KB |
Output is correct |
| 2 |
Incorrect |
33 ms |
47360 KB |
Output isn't correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
34 ms |
47360 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1443 ms |
162256 KB |
Output isn't correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
32 ms |
47360 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1587 ms |
262148 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1507 ms |
94688 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1538 ms |
98548 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
205 ms |
52344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1512 ms |
93608 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
1575 ms |
95992 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
