# 维护两个并查集
from collections import defaultdict
# 如果最终两个数在同一集合内，相同
# 如果不在同一集合内，不同

t = int(input())
maxN = 200010

def find(x):
    if p[x] != x: p[x] = find(p[x])
    return p[x]

for _ in range(t):
    n = int(input())
    p = [__ for __ in range(maxN)]
    Tag = False
    dic = defaultdict(set)
    cnt = 1
    exist = defaultdict(int)
    for __ in range(n):
        i, j, e = map(int, input().split())
        if i not in exist:
            exist[i] = cnt
            cnt += 1
        if j not in exist:
            exist[j] = cnt
            cnt += 1
        dic[e].add((exist[i], exist[j]))

    # 把所有相等的数合并到各自的集合内
    for i, j in dic[1]:
        pi, pj = find(i), find(j)
        # i == j
        p[pi] = pj
    for i, j in dic[0]:
        # i != j
        pi, pj = find(i), find(j)
        if p[pi] == p[pj]:
            print('NO')
            Tag = True
            break
    if Tag: continue
    print('YES')