delete pics to save space

8.4195.cpp

@@ -0,0 +1,50 @@
+#include<cstdio>
+#include<algorithm>
+#include<cstring>
+using namespace std;
+const int maxn=1000005;
+int T,n,x[maxn],y[maxn],z[maxn],a[maxn*2],cnt,fa[maxn*2];
+inline int ff(int u)
+{
+	int a=u,b;
+	while(u!=fa[u]) u=fa[u];
+	while(a!=u)
+	{
+		b=fa[a];
+		fa[a]=u;
+		a=b;
+	}
+	return u;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		scanf("%d",&n);
+		for(int i=1;i<=n;i++) scanf("%d%d%d",&x[i],&y[i],&z[i]);
+		cnt=0;
+		for(int i=1;i<=n;i++) a[++cnt]=x[i],a[++cnt]=y[i];
+		sort(a+1,a+1+cnt);
+		cnt=unique(a+1,a+1+cnt)-(a+1);
+		for(int i=1;i<=n;i++)
+		{
+			x[i]=lower_bound(a+1,a+1+cnt,x[i])-a;
+			y[i]=lower_bound(a+1,a+1+cnt,y[i])-a;
+		}
+		for(int i=1;i<=cnt;i++) fa[i]=i;
+		int flg=1;
+		for(int i=1;i<=n;i++) if(z[i]==1)
+		{
+			int a=ff(x[i]),b=ff(y[i]);
+			if(a!=b) fa[a]=b;
+		}
+		for(int i=1;i<=n;i++) if(z[i]==0)
+			if(ff(x[i])==ff(y[i])) { flg=0; break; }
+		puts(flg?"YES":"NO");
+	}
+	return 0;
+}