[UVA] 10608 - Friends

/* 題目: UVa 10608 - Friends

 * Language: C++

 * Created on: 2015年12月4日

 *   Author: hanting

 */

#include <iostream>

#include <vector>

using namespace std;

vector<vector<int> > node;

vector<bool> visit;

void ConnectNode(int a, int b)

{

    node[a].push_back(b);

    node[b].push_back(a);

}

int DFS(int cur)

{

    visit[cur] = 1;

    int cnt = 1;

    for(int i = 0; i < node[cur].size(); i++)

    {

        int tmp = node[cur][i];

        if(!visit[tmp])

        {

            cnt += DFS(tmp);

        }

    }

    return cnt;

}

int main()

{

    int testCase = 0;

    cin >> testCase;

    while(testCase--)

    {

        int manN, pairN;

        cin >> manN >> pairN;

        visit.assign(manN+1, 0);

        node.assign(manN+1, vector<int>());

        for(int i = 0; i < pairN; i++)

        {

            int a, b;

            cin >> a >> b;

            ConnectNode(a, b);

        }

        int maxi = 0;

        for(int i = 1; i <= manN; i++)

        {

            if(!visit[i])

            {

                int groupNum = DFS(i);

                maxi = max(maxi, groupNum);

            }

        }

        cout << maxi << endl;

    }

    return 0;

}