2019年南京工业大学828数据结构第三题

#include <iostream>
using namespace std;
int map[105][105];
int vis[105];
int n, m;
void Dfs(int pos)
{
    vis[pos] = 1;
    for (int i = 1; i <= n; i++)
    {
        if (map[pos][i] == 1 && vis[i] == 0)
        {
            Dfs(i);
        }
    }
}
int main()
{

    cin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        vis[i] = 0;
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
        {
            if (i == j)
            {
                map[i][j] = 1;
            }
            else
            {
                map[i][j] = 0;
            }
        }
    }
    for (int i = 0; i < m; i++)
    {
        int s, d;
        cin >> s >> d;
        map[s][d] = 1;
        map[d][s] = 1;
    }
    int cnt = 0;
    for (int i = 1; i <= n; i++)
    {
        if (vis[i] == 0)
        {
            Dfs(i);
            cnt++;
        }
    }
    cout << cnt << endl;
    return 0;
}