#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
using ll = long long;

void solve() {
    int n;
    cin >> n;
    vector<ll> weight(n + 1);
    for(int i = 1; i <= n; i++) cin >> weight[i];
    vector<vector<pair<int, ll>>> g(n + 1);
    for(int i = 1; i < n; i++) {
        int u, v, w; cin >> u >> v >> w;
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }
    int root = 1;
    for(int i = 1; i <= n; i++) {
        if(g[i].size() == 1) {
            root = 1;
            break;
        }
    }

    ll ans = LLONG_MIN;
    auto dfs = [&](auto&& self, int u, int p) -> ll {
        if(g[u].size() == 1 && g[u][0].first == p) { // leaf
            return weight[u];
        }
        priority_queue<ll> pq;
        ll mx = LLONG_MIN;
        for(auto &[v, w]: g[u]) {
            if(v == p) continue;
            ll x = self(self, v, u);
            mx = max(mx, (weight[u] - 2 * w) + x);
            pq.push((weight[u] - 2 * w) + x);
        }
        if(pq.size() >= 2) {
            ll x = pq.top(); pq.pop();
            x += pq.top() - weight[u];
            ans = max(ans, x);
        }
        ans = max(ans, mx);
        return mx;
    };
    dfs(dfs, root, 0);
    cout << ans << endl;
    return;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(0);
    int tc = 1;
    cin >> tc;
    for (int t = 1; t <= tc; t++) {
        // cout << "Case " << t << ": ";
        solve();
    }
    return 0;
}