delete pics to save space

1.3209.cpp

@@ -0,0 +1,73 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=10005;
+int T,n,m,u[maxn],v[maxn],id[maxn],vis[maxn],fa[maxn*2];
+bool cr(int x1, int x2, int y1, int y2)
+{
+    if(x1==x2||y1==y2||x1==y2||x2==y1) return 0;
+    return (x1<x2&&y1<y2&&x2<y1)||(x2<x1&&y2<y1&&x1<y2);
+}
+inline int ff(int x)
+{
+	int a=x,b;
+	while(x!=fa[x]) x=fa[x];
+	while(a!=x)
+	{
+		b=fa[a];
+		fa[a]=x;
+		a=b;
+	}
+	return x;
+}
+inline void merge(int x,int y)
+{
+	x=ff(x); y=ff(y);
+	if(x!=y) fa[y]=x;
+}
+int main()
+{
+#ifdef local
+	freopen("in.txt","r",stdin);
+#endif
+	scanf("%d",&T);
+	while(T-->0)
+	{
+		scanf("%d%d",&n,&m);
+		for(int i=1;i<=m;i++) scanf("%d%d",&u[i],&v[i]);
+		for(int i=1;i<=n;i++)
+		{
+			int x; scanf("%d",&x);
+			id[x]=i;
+		}
+		if(m>3*n-6) { puts("NO"); continue; }
+		for(int i=1;i<=m;i++)
+		{
+			int x=id[u[i]],y=id[v[i]];
+			if(x>y) swap(x,y);
+			u[i]=x; v[i]=y;
+		}
+		for(int i=1;i<=m;i++) vis[i]=(u[i]%n+1==v[i]);
+		for(int i=1;i<=m*2;i++) fa[i]=i;
+		for(int i=1;i<=m;i++)
+		{
+			if(vis[i]) continue;
+			for(int j=1;j<=m;j++)
+			{
+				if(vis[j]) continue;
+				if(!cr(u[i],u[j],v[i],v[j])) continue;
+				if(ff(i)==ff(j))
+				{
+					puts("NO");
+					goto nxt;
+				}
+				merge(i,j+m);
+				merge(j,i+m);
+			}
+		}
+		puts("YES");
+		nxt:;
+	}
+	return 0;
+}