delete pics to save space

history_source/信息学奥赛一本通/3.4.5.2.cpp

@@ -0,0 +1,69 @@
+#include<cstdio>
+#define maxn 1000
+int fa[maxn+1],size[maxn+1],dan=1,sum,n,s,a,k;
+int tu[maxn+1][maxn+1],num[maxn+1];
+inline int max(int aa,int bb)
+{return aa>bb?aa:bb;}
+int ff(int a)
+{
+	static int t1,t2;
+	t1=a;
+	while(fa[a]!=a) a=fa[a];
+	while(t1!=a)
+	{
+		t2=fa[t1];
+		fa[t1]=a;
+		t1=t2;
+	}
+	return a;
+}
+void un(int a,int b)
+{
+	static int aa,bb;
+	aa=ff(a);
+	bb=ff(b);
+	if(aa!=bb)
+	{
+		fa[bb]=aa;
+		size[aa]+=size[bb];
+		dan=max(dan,size[aa]);
+	}
+}
+int main()
+{
+	freopen("black.in","r",stdin);
+	freopen("black.out","w",stdout);
+	int i,j;
+	scanf("%d",&n);
+	for(i=1;i<=n;i++) fa[i]=i,size[i]=1;
+	sum=n;
+	for(i=1;i<=n;i++)
+	{
+		scanf("%d",&s);
+		for(j=0;j<s;j++)
+		{
+			scanf("%d",&a);
+			tu[i][num[i]++]=a;
+			tu[a][num[a]++]=i;
+		}
+	}
+	k=n;
+	while(dan<=n/2)
+	{
+		k--;
+		for(i=0;i<num[k+1];i++)
+			if(tu[k+1][i]>k) un(k+1,tu[k+1][i]);
+	}
+	printf("%d\n",k+1);
+	return 0;
+}
+/*
+7
+2 2 5
+3 1 3 4
+2 2 4
+2 2 3
+3 1 6 7
+2 5 7
+2 5 6
+*/