overkill | not recommended

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
#define pb push_back
#define ff first
#define ss second
const int N=2e3+7;
const int mod=1e9+7;
const double eps=1e-9;
const double pi=    3.14159265358979323846;
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    op_set;

int ans=0;

map<int,int> dfs(int node,int parent,vector<vector<pair<int,int>>>&g,bool conn,int curr)
{
    if(curr==0 && conn==1)
        ans++;

    map<int,int> mp;
    mp[curr]++;
    for(auto &[child,wt] : g[node])
    {
        if(child!=parent)
        {
            if(wt==0)
            {
                auto cmp=dfs(child,node,g,0,(curr^wt));
                int best=0;
                for(auto &[val,freq] : cmp)
                    best=std::max(best,freq);
                ans+=best;
            }
            else
            {
                auto cmp=dfs(child,node,g,conn,(curr^wt));
                if(mp.size()<cmp.size())
                    swap(mp,cmp);
                for(auto &[val,freq] : cmp)
                    mp[val]+=freq;
            }
        }
    }

    return mp;
}

int32_t main()
{
   ios_base::sync_with_stdio(false);
   cin.tie(0);

   int t;
   cin >> t;
   while(t--)
   {
        int n;
        cin >> n;
        vector<vector<pair<int,int>>> g(n+1);
        for(int i=1;i<n;i++)
        {
            int a,b,wt;
            cin >> a >> b >> wt;
            g[a].pb({b,wt});
            g[b].pb({a,wt});
        }

        ans=0;
        dfs(1,0,g,1,0);

        cout << ans-1 << "\n";
   }
}

/*
God is King, we the soldiers , Ultra beam out the solar
When I get to Heaven's gates . I ain't gotta peak over
I ain't mean, I'm just focused
Before the flood, people judge , They did the same thing to Noah
*/