#include "traffic.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 3;
int n, *p, *s, *d, sz[N], sum_all = 0, ans, ver_ans;
vector<int> adj[N];
void dfs_solve(int u, int par = -1){
int sum = 0, mx = 0;
for(int to: adj[u])
if(to != par){
dfs_solve(to, u);
mx = max(mx, sz[to]);
sum += sz[to];
}
mx = max(mx, sum_all - sum - p[u]);
if(mx < ans){
ans = mx;
ver_ans = u;
}
}
void dfs_sz(int u, int par = -1){
sz[u] = p[u];
for(int to: adj[u])
if(to != par){
dfs_sz(to, u);
sz[u] += sz[to];
}
}
int LocateCentre(int _n, int _p[], int _s[], int _d[]) {
n = _n, p = _p, s = _s, d = _d;
for(int i = 0; i < n; ++i)
adj[i].clear();
for(int i = 0; i < n - 1; ++i){
adj[s[i]].push_back(d[i]);
adj[d[i]].push_back(s[i]);
}
sum_all = 0, ans = INT_MAX;
for(int i = 0; i < n; ++i)
sum_all += p[i];
dfs_sz(0);
dfs_solve(0);
return ver_ans;
}
/*
5
10 10 10 20 20
0 2
1 2
2 3
3 4
*/
