#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 +5;

int T, n, a[N], xx[N] , yy[N] , zz[N];
map<int, int> fa;

int find(int x){
	return fa[x] = (fa[x] == x)? (x) : (find(fa[x]));
}
void merge(int a, int b){
	fa[find(a)] = find(b);
}

int main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	cin >> T;
	while(T --){
		fa.clear();
		cin >> n;
		for(int i = 1;i <= n;i ++){
			int xx[i], yy[i], zz[i];
			cin >>xx[i] >> yy[i] >>zz[i];
            fa[xx[i]] = xx[i], fa[yy[i]] = yy[i];
		}
        for(int i = 1; i <= n ; i++){
            if(zz[i]){
				merge(xx[i], yy[i]);
			}
        }
		bool flag = 0;
		for(int i = 1;i <= n;i ++){
			if(!zz[i]){
				int fx = find(xx[i]), fy = find(yy[i]);
				if(fx == fy){
					flag = 1;
					break;
				}
			}
		}
		if(flag)cout << "NO" << endl;
        else cout << "YES" << endl;
	}
	return 0;
}

并查集做的，大佬们求助