#include<bits/stdc++.h>
using namespace std;
#define IOS ios::sync_with_stdio(false);; cin.tie(NULL)
void selfMax(long long& a, long long b){
a = max(a, b);
}
void selfMin(long long& a, long long b){
a = min(a, b);
}
template<typename T> istream& operator>>(istream& in, vector<T>& a) {for(auto &x : a) in >> x; return in;};
template<typename T1, typename T2> istream& operator>>(istream& in, pair<T1, T2>& x) {return in >> x.first >> x.second;}
template<typename T1, typename T2> ostream& operator<<(ostream& out, const pair<T1, T2>& x) {return out << x.first << ' ' << x.second;}
template<typename T> ostream& operator<<(ostream& out, vector<T>& a) {for(auto &x : a) out << x << ' '; return out;};
template<typename T> ostream& operator<<(ostream& out, vector<vector<T> >& a) {for(auto &x : a) out << x << '\n'; return out;};
template<typename T1, typename T2> ostream& operator<<(ostream& out, vector<pair<T1, T2> >& a) {for(auto &x : a) out << x << '\n'; return out;};
/*
Use DSU dsu(N);
*/
struct DSU {
vector<long long> e;
DSU(long long N) { e = vector<long long>(N, -1); }
// get representive component (uses path compression)
long long get(long long x) { return e[x] < 0 ? x : e[x] = get(e[x]); }
bool same_set(long long a, long long b) { return get(a) == get(b); }
long long size(long long x) { return -e[get(x)]; }
bool unite(long long x, long long y) { // union by size
x = get(x), y = get(y);
if (x == y) return false;
if (e[x] > e[y]) swap(x, y);
e[x] += e[y]; e[y] = x;
return true;
}
};
/*
Run with Bit<long long> BIT
*/
template <class T> class BIT {
private:
long long size;
vector<T> bit;
vector<T> arr;
public:
BIT(long long size) : size(size), bit(size + 1), arr(size) {}
void set(long long ind, long long val) { add(ind, val - arr[ind]); }
void add(long long ind, long long val) {
arr[ind] += val;
ind++;
for (; ind <= size; ind += ind & -ind) { bit[ind] += val; }
}
T pref_sum(long long ind) {
ind++;
T total = 0;
for (; ind > 0; ind -= ind & -ind) { total += bit[ind]; }
return total;
}
};
/*
Change Comb for specific Seg tree probs, but run with Seg<long long> Seg;
*/
template<class T> struct Seg {
const T ID = 1e18; T comb(T a, T b) { return min(a,b); }
long long n; vector<T> seg;
void init(long long _n) { n = _n; seg.assign(2*n,ID); }
void pull(long long p) { seg[p] = comb(seg[2*p],seg[2*p+1]); }
void upd(long long p, T val) {
seg[p += n] = val; for (p /= 2; p; p /= 2) pull(p); }
T query(long long l, long long r) {
T ra = ID, rb = ID;
for (l += n, r += n+1; l < r; l /= 2, r /= 2) {
if (l&1) ra = comb(ra,seg[l++]);
if (r&1) rb = comb(seg[--r],rb);
}
return comb(ra,rb);
}
};
const long long N = 1000001;
long long n;
vector<long long> adj[N];
long long magic[N];
long long dp[2][N];
long long up[N];
pair<long long, long long> ans = make_pair(1e9, 1);
void dfs(long long u, long long p){
for(long long v : adj[u]){
if(v != p){
dfs(v, u);
if(magic[v] == 1){
if(dp[0][u] < dp[0][v] + 1){
dp[1][u] = dp[0][u];
dp[0][u] = dp[0][v] + 1;
}
else if(dp[1][u] < dp[0][v] + 1){
dp[1][u] = dp[0][v] + 1;
}
}
}
}
}
void dfs2(long long u, long long p){
for(long long v : adj[u]){
if(v != p){
if(magic[u] == 1){
up[v] = up[u] + 1;
if(magic[v] == 1){
if(dp[0][v] + 1 == dp[0][u]){
up[v] = max(up[v], dp[1][u] + 1);
}
}
else{
up[v] = max(up[v], dp[0][u] + 1);
}
}
dfs2(v, u);
}
}
vector<long long> v;
v.push_back(up[u]);
v.push_back(dp[0][u]);
v.push_back(dp[1][u]);
sort(v.begin(), v.end(), greater<long long>());
if(ans.first * (v[0] + v[1] + 1) > ans.second * magic[u]){
ans = make_pair(magic[u], (v[0] + v[1] + 1));
}
}
int main(){
long long n;
cin >> n;
for(long long i = 0; i < n - 1; i++){
long long a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for(long long i = 1; i <= n; i++){
cin >> magic[i];
}
dfs(1, 0);
dfs2(1, 0);
cout << ans.first/__gcd(ans.first, ans.second) << "/" << ans.second/__gcd(ans.first, ans.second) << "\n";
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
12 ms |
23764 KB |
Output is correct |
| 2 |
Correct |
12 ms |
23816 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
12 ms |
23812 KB |
Output is correct |
| 2 |
Correct |
12 ms |
23892 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
689 ms |
117712 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
23764 KB |
Output is correct |
| 2 |
Correct |
809 ms |
209668 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
802 ms |
191620 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
720 ms |
86024 KB |
Output is correct |
| 2 |
Correct |
534 ms |
81008 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
745 ms |
88368 KB |
Output is correct |
| 2 |
Correct |
98 ms |
32204 KB |
Output is correct |
| 3 |
Correct |
834 ms |
213376 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
91 ms |
30668 KB |
Output is correct |
| 2 |
Correct |
729 ms |
102320 KB |
Output is correct |
| 3 |
Correct |
475 ms |
65892 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
689 ms |
82660 KB |
Output is correct |
| 2 |
Correct |
736 ms |
102236 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
761 ms |
87160 KB |
Output is correct |
| 2 |
Correct |
481 ms |
65716 KB |
Output is correct |
