Social Cluster

#include<bits/stdc++.h>
using namespace std;

const int Max=1010;
int father[Max];
int height[Max];
int n,course[Max],isroot[Max];

void Initial() {
	for(int i=1; i<=n; i++) {
		father[i]=i;
		height[i]=0;
	}
}

int Find(int x) {
	if(x!=father[x]) {
		father[x]=Find(father[x]);
	}
	return father[x];
}

void Union(int x,int y) {
	x=Find(x);
	y=Find(y);
	if(x!=y) {
		if(height[x]>height[y]) {
			father[y]=x;
		} else if(height[y]>height[x]) {
			father[x]=y;
		} else {
			father[x]=y;
			height[y]++;
		}
	}
	return ;
}

int main() {
	int k,x;
	scanf("%d",&n);
	Initial();
	for(int i=1; i<=n; i++) {
		scanf("%d:",&k);
		for(int j=0; j<k; j++) {
			scanf("%d",&x);
			if(course[x]==0) {
				course[x]=i;
			}
			Union(i,Find(course[x]));
		}
	}
	for(int i=1; i<=n; i++) {
		isroot[Find(i)]++;
	}
	int component=0;
	for(int i=1; i<=n; i++) {
		if(isroot[i]!=0) {
			component++;
		}
	}
	printf("%d\n",component);
	sort(isroot+1,isroot+n+1,greater<int>());
	for(int i=1; i<=component; i++) {
		printf("%d",isroot[i]);
		if(i<component) printf(" ");
	}
	return 0;
}