1 #include<bits/stdc++.h>

 2 using namespace std;

 3 const int N=1e6+10;

 4 int t,n,fa[N],b[N*3];

 5 struct node{

 6     int x,y,e;

 7 }a[N];

 8 bool cmp(node a,node b){//e=1的放在前面

 9     return a.e>b.e;

10 }

11 int get(int x){

12     return fa[x]==x?fa[x]:fa[x]=get(fa[x]);

13 }

14 int main(){

15     scanf("%d",&t);

16     while(t--){

17         int tot=0;

18         memset(b,0,sizeof(b));

19         memset(a,0,sizeof(a));

20         memset(fa,0,sizeof(fa));

21         int vis=1;

22         scanf("%d",&n);

23         for(int i=1;i<=n;i++){

24             scanf("%d%d%d",&a[i].x,&a[i].y,&a[i].e);

25             b[++tot]=a[i].x;b[++tot]=a[i].y;

26         }

27         sort(b+1,b+tot+1);

28         int cnt=unique(b+1,b+tot+1)-b-1;

29         for(int i=1;i<=n;i++){

30             a[i].x=lower_bound(b+1,b+cnt+1,a[i].x)-b;

31             a[i].y=lower_bound(b+1,b+cnt+1,a[i].y)-b;

32         }

33         for(int i=1;i<=cnt;i++) fa[i]=i;

34         sort(a+1,a+n+1,cmp);

35         for(int i=1;i<=n;i++){

36             int r1=get(a[i].x);

37             int r2=get(a[i].y);

38             if(a[i].e){

39                 fa[r1]=r2;

40             }

41             else if(r1==r2){

42                 cout<<"NO"<<endl;

43                 vis=0;

44                 break;

45             }

46         }

47         if(vis) cout<<"YES"<<endl;

48     }

49 }