UVa01197.cpp

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
// shortcuts for "common" data types in contests
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
#define INF 1000000000

class UnionFind {                                              // OOP style
private:
  vi p, rank, setSize;                       // remember: vi is vector<int>
  int numSets;
public:
  UnionFind(int N) {
    setSize.assign(N, 1); numSets = N; rank.assign(N, 0);
    p.assign(N, 0); for (int i = 0; i < N; i++) p[i] = i; }
  int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); }
  bool isSameSet(int i, int j) { return findSet(i) == findSet(j); }
  void unionSet(int i, int j) { 
    if (!isSameSet(i, j)) { numSets--; 
    int x = findSet(i), y = findSet(j);
    // rank is used to keep the tree short
    if (rank[x] > rank[y]) { p[y] = x; setSize[x] += setSize[y]; }
    else                   { p[x] = y; setSize[y] += setSize[x];
                             if (rank[x] == rank[y]) rank[y]++; } } }
  int numDisjointSets() { return numSets; }
  int sizeOfSet(int i) { return setSize[findSet(i)]; }
};

int main()
{
    int n, m; scanf("%d %d\n", &n, &m);
	while (n != 0)
	{
		UnionFind students(n);
		while (m--)
		{
			int nS, a; scanf("%d %d", &nS, &a);
			while (--nS)
			{
				int b; scanf(" %d", &b);
				students.unionSet(a, b);
			}
			scanf("\n");
		}
		printf("%d\n", students.sizeOfSet(0));
		
		scanf("%d %d", &n, &m);
	}
    
	return 0;
}