#include<stdio.h>

#include<algorithm>

#include<string.h>

#include<map>

using namespace std;

int fa[],n,sum[],tot,T;

map<int,int> old,tong;

struct node

{

    int x,y,c;

}a[];

template<class T>void read(T &x)

{

    x=;char ch=getchar();

    while(ch<''||ch>'')  ch=getchar();

    while(ch>=''&&ch<=''){x=(x<<)+(x<<)+(ch^);ch=getchar();}

}

int find(int x)

{

    int p=x,q;

    while(x!=fa[x])

      x=fa[x];

    while(p!=x)

    {

        q=fa[p];

        fa[p]=x;

        p=q;

    }

    return x;

}

int main()

{

    read(T);

    while(T--)

    {

        old.clear();tong.clear();tot=;bool flag=;

        read(n);

        for(int i=;i<=n;i++)

        {

            read(a[i].x);read(a[i].y);read(a[i].c);

            if(tong[a[i].x]==)

            {

                tong[a[i].x]=;

                sum[++tot]=a[i].x;

            }

            if(tong[a[i].y]==)

            {

                tong[a[i].y]=;

                sum[++tot]=a[i].y;

            }

        }

        sort(sum+,sum++tot);

        for(int i=;i<=tot;i++) old[sum[i]]=i;

        for(int i=;i<=n;i++)

        {

            a[i].x=old[a[i].x];

            a[i].y=old[a[i].y];

        }

        for(int i=;i<=tot;i++) fa[i]=i;

        for(int i=;i<=n;i++)

        {

            int p=find(a[i].x),q=find(a[i].y);

            if(a[i].c==&&p!=q) fa[p]=q;

            if(a[i].c!=&&p==q){flag=;break;}

        }

        if(flag==){printf("NO\n");continue;}

        for(int i=;i<=n;i++)

        {

            int p=find(a[i].x),q=find(a[i].y);

            if(a[i].c==&&p!=q){flag=;break;}

            if(a[i].c==&&p==q){flag=;break;}

        }

        if(flag==)printf("NO\n");

        else printf("YES\n");

    }

    return ;

}