题目描述

C++代码

样例

#include<iostream>
#include<algorithm>
#include<string>
#include<unordered_set>
#include<cstring>
#include<vector>
using namespace std;
const int N = 1e4 + 10;
int parent[N];
void Init(int n)
{
    for (int i = 1; i <= n; i++)
    {
        parent[i] = i;
    }
}
int find(int a)
{
    if (a != parent[a]) {
        parent[a] = find(parent[a]);
    }
    return parent[a];
}
void Unite(int x, int y)
{
    int root_x = find(x);
    int root_y = find(y);
    if (root_x != root_y)
    {
        parent[root_x] = root_y;
    }
}
int main()
{
    int T;
    int sum = 0;
    unordered_set<int> st;
    cin >> T;
    int o = -1;
    vector<vector<int>> a(T);
    for(int i=0;i<T;i++)
    {
        int n;
        cin >> n;
        for (int j = 0; j < n; j++)
        {
            int x;
            cin >> x;
            a[i].push_back(x);
            o = max(o, x);
            st.insert(x);
        }

    }
    Init(o);
    for (int i = 0; i < T; i++)
    {
        for (int j = 1; j < a[i].size(); j++)
        {
            Unite(a[i][j], a[i][j - 1]);
        }
    }
    for (int i=1;i<=o;i++)
    {
        if (parent[i] == i) {
            sum++;
        }
    }
    cout << sum << " " << st.size() << endl;
    int k;
    cin >> k;
    for (int i = 0; i < k; i++)
    {
        int x, y;
        cin >> x >> y;
        if (find(x) != find(y))
        {
            cout << "No" << endl;
        }
        else {
            cout << "Yes" << endl;
        }
    }
    return 0;
}