#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
vector<int> adj[maxn], len[maxn];
int a[maxn], dp[maxn];
int n;
void add(int x, int t) {
if (len[x][0] <= t) swap(len[x][0], t);
len[x][1] = max(len[x][1], t);
}
int get(int x, int t=0) {return (a[x] == 1) * (len[x][t] + 1);}
int dfs(int x, int p = 0) {
len[x] = {0, 0};
for (int v : adj[x]) {
if (v == p) continue;
add(x, dfs(v, x));
}
return get(x);
}
int dfs_root(int x, int p = 0) {
if (p) {
int l = (a[p] == 1) * get(p, len[p][0] == get(x));
add(x, l);
}
dp[x] = len[x][0] + len[x][1];
for (int v : adj[x]) {
if (v == p) continue;
dfs_root(v, x);
}
}
int main() {
cin >> n
for (int i = 1; i < n; i++) {
int a, b; cin >> a >> b;
g[a].emplace_back(b);
g[b].emplace_back(a);
}
for (int i = 1; i <= n; ++i) cin >> a[i];
dfs(1);
dfs_root(1);
int x = -1, y = -1;
for (int i = 1; i <= n; ++i) {
if (x == -1 or x *1ll* (dp[i] + 1) > a[i] *1ll* y) {
x = a[i];
y = dp[i] + 1;
}
}
int g = __gcd(x, y);
cout << x/g << '/' << y/g << '\n';
return 0;
}
Compilation message
mag.cpp: In function 'int dfs_root(int, int)':
mag.cpp:34:1: warning: no return statement in function returning non-void [-Wreturn-type]
34 | }
| ^
mag.cpp: In function 'int main()':
mag.cpp:37:10: error: expected ';' before 'for'
37 | cin >> n
| ^
| ;
38 | for (int i = 1; i < n; i++) {
| ~~~
mag.cpp:38:18: error: 'i' was not declared in this scope
38 | for (int i = 1; i < n; i++) {
| ^
