[NHSPC 2019] C. 尋寶之旅

// #pragma GCC target("avx2")
#pragma GCC optimize("O3", "unroll-loops")

// #include <bits/extc++.h>
// using namespace __gnu_pbds;

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define double long double
// template <typename T>
// using pbds_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using pii = pair<int, int>;
template<typename T>
using prior = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using Prior = priority_queue<T>;

#define X first
#define Y second
#define ALL(x) (x).begin(), (x).end()
#define eb emplace_back
#define pb push_back

#define fastIO() ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define RANDOM() random_device __rd; \
                 mt19937 __gen = mt19937(__rd()); \
                 uniform_int_distribution<int> __dis(0, 1); \
                 auto rnd = bind(__dis, __gen);

const int INF = 1E18;
const int mod = 1E9 + 7;
const int maxn = 2E5 + 5;

int ans = 0;
vector<int> v(maxn);
vector<int> adj[maxn];
map<int, int> cnt;

void dfs(int now, int lst) {
    ans = max(ans, ++cnt[v[now]]);
    for (auto x : adj[now]) {
        if (x != lst) dfs(x, now);
    }
    --cnt[v[now]];
}

int32_t main() {
    fastIO();

    int n, a, b;
    cin >> n;

    for (int i = 0; i < n; ++i) cin >> v[i];
    for (int i = 0; i < n-1; ++i) {
        cin >> a >> b, adj[a].eb(b), adj[b].eb(a);
    }

    dfs(0, -1);

    cout << ans << "\n";

    return 0;
}