1 #include<cstdio>
 2 #include<cstring>
 3 #include<cmath>
 4 #include<ctime>
 5 #include<cstdlib>
 6 #include<iostream>
 7 #include<algorithm>
 8 #include<set>
 9 #define clr(a,x) memset(a,x,sizeof(a))
10 #define rep(i,l,r) for(int i=l;i<r;i++)
11 using namespace std;
12 int read()
13 {
14     char c=getchar();
15     int ans=0,f=1;
16     while(!isdigit(c)){
17         if(c=='-') f=-1;
18         c=getchar();
19     }
20     while(isdigit(c)){
21         ans=ans*10+c-'0';
22         c=getchar();
23     }
24     return ans*f;
25 }
26 const int maxn=200005;
27 int f[maxn],a[maxn][3],b[maxn][2],c[maxn];
28 int find(int a)
29 {
30     return (f[a]==a?f[a]:f[a]=find(f[a]));
31 }
32 int main()
33 {
34     freopen("prog10.in","r",stdin);
35     freopen("prog10.out","w",stdout);
36     int t=read();
37     while(t--){
38         int n=read(),cnt=0,cnt1=0;
39         bool flag=1;
40         clr(a,0),clr(b,0),clr(c,0);
41         rep(i,0,maxn) f[i]=i;
42         rep(i,0,n){
43             a[i][0]=read();
44             a[i][1]=read();
45             a[i][2]=read();
46             if(!a[i][2]){
47                 b[cnt][0]=a[i][0];
48                 b[cnt++][1]=a[i][1];
49             }
50             c[cnt1++]=a[i][0];
51              c[cnt1++]=a[i][1];
52         }
53         cnt1=unique(c,c+(n<<1))-c;
54         sort(c,c+cnt1);
55         rep(i,0,n){
56             if(a[i][2]==1){
57                 f[find(lower_bound(c,c+cnt1,a[i][0])-c)]=find(lower_bound(c,c+cnt1,a[i][1])-c);
58             }
59         }
60         rep(i,0,cnt){
61             if(find(lower_bound(c,c+cnt1,b[i][0])-c)==find(lower_bound(c,c+cnt1,b[i][1])-c)){
62                 flag=0;break;
63             }
64         }
65         if(flag) printf("YES\n");
66         else printf("NO\n");
67     }
68     return 0;
69 }

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<cmath>
 4 #include<ctime>
 5 #include<cstdlib>
 6 #include<iostream>
 7 #include<algorithm>
 8 #include<set>
 9 #define clr(a,x) memset(a,x,sizeof(a))
10 #define rep(i,l,r) for(int i=l;i<r;i++)
11 using namespace std;
12 int read()
13 {
14     char c=getchar();
15     int ans=0,f=1;
16     while(!isdigit(c)){
17         if(c=='-') f=-1;
18         c=getchar();
19     }
20     while(isdigit(c)){
21         ans=ans*10+c-'0';
22         c=getchar();
23     }
24     return ans*f;
25 }
26 set<int>S;
27 const int maxn=200005;
28 int f[maxn],a[maxn][3],b[maxn][2],c[maxn];
29 int find(int a)
30 {
31     return (f[a]==a?f[a]:f[a]=find(f[a]));
32 }
33 int main()
34 {
35     freopen("prog10.in","r",stdin);
36     freopen("prog10.out","w",stdout);
37     int t=read();
38     while(t--){
39         S.clear();
40         int n=read(),cnt=0,cnt1=0;
41         bool flag=1;
42         clr(a,0),clr(b,0),clr(c,0);
43         rep(i,0,n<<1) f[i]=i;
44         rep(i,0,n){
45             a[i][0]=read();
46             a[i][1]=read();
47             a[i][2]=read();
48             if(!a[i][2]){
49                 b[cnt][0]=a[i][0];
50                 b[cnt++][1]=a[i][1];
51             }
52             if(S.find(a[i][0])==S.end()){
53                 S.insert(a[i][0]);
54                 c[cnt1++]=a[i][0];
55             }
56             if(S.find(a[i][1])==S.end()){
57                 S.insert(a[i][1]);
58                 c[cnt1++]=a[i][1];
59             }
60         }
61         sort(c,c+cnt1);
62         rep(i,0,n){
63             if(a[i][2]==1){
64                 f[find(lower_bound(c,c+cnt1,a[i][0])-c)]=find(lower_bound(c,c+cnt1,a[i][1])-c);
65             }
66         }
67         rep(i,0,cnt){
68             if(find(lower_bound(c,c+cnt1,b[i][0])-c)==find(lower_bound(c,c+cnt1,b[i][1])-c)){
69                 flag=0;break;
70             }
71         }
72         if(flag) printf("YES\n");
73         else printf("NO\n");
74     }
75     return 0;
76 }