Problem:
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Connected Components

Write a program which reads relations in a SNS (Social Network Service), and judges that given pairs of users are reachable each other through the network.

Input

In the first line, two integer $n$ and $m$ are given. $n$ is the number of users in the SNS and $m$ is the number of relations in the SNS. The users in the SNS are identified by IDs $0, 1, ..., n-1$.

In the following $m$ lines, the relations are given. Each relation is given by two integers $s$ and $t$ that represents $s$ and $t$ are friends (and reachable each other).

In the next line, the number of queries $q$ is given. In the following $q$ lines, $q$ queries are given respectively. Each query consists of two integers $s$ and $t$ separated by a space character.

Output

For each query, print "yes" if $t$ is reachable from $s$ through the social network, "no" otherwise.

Constraints

$2 \leq n \leq 100,000$

$0 \leq m \leq 100,000$

$1 \leq q \leq 10,000$

Sample Input

10 9
0 1
0 2
3 4
5 7
5 6
6 7
6 8
7 8
8 9
3
0 1
5 9
1 3

Sample Output

yes
yes
no

Solution in C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
					
public class Program
{
	static int[] color;
	
	public static void Main()
	{
		int[] tmp = Array.ConvertAll(Console.ReadLine().Split(" ".ToCharArray()), int.Parse);
		int n = tmp[0];
		int m = tmp[1];
		
		Node[] nodes = new Node[n];
		for(int i = 0; i < n; i++) {
			nodes[i] = new Node(i);
		}
		color = new int[n];
		
		for(int i = 0; i < m; i++) {
			tmp = Array.ConvertAll(Console.ReadLine().Split(" ".ToCharArray()), int.Parse);
			int s = tmp[0];
			int t = tmp [1];
			
			nodes[s].Children.Add(nodes[t]);
			nodes[t].Children.Add(nodes[s]);
		}
		
		AssignColor(nodes);
		
		int q = int.Parse(Console.ReadLine());
		StringBuilder sb = new StringBuilder();
		for(int i = 0; i < q; i++) {
			
			tmp = Array.ConvertAll(Console.ReadLine().Split(" ".ToCharArray()), int.Parse);
			int s = tmp[0];
			int t = tmp [1];

			sb.AppendLine( (color[s] == color[t])? "yes" : "no" );
		}
		Console.Write(sb);
	}
	
	static void AssignColor(Node[] nodes)
	{
		int rootId = 0;
		
		for(int i = 0; i < nodes.Length; i++) {
			if(color[i] == 0) DFS(nodes[i], ++rootId);
		}
	}
	
	static void DFS(Node r, int c)
	{
		var S = new Stack<Node>();
		
		S.Push(r);
		color[r.Id] = c;
		
		while(S.Any())
		{
			Node u = S.Pop();
			
			foreach (var d  in u.Children) {
				if(color[d.Id] == 0) { 
					S.Push(d);
					color[d.Id] = c;
				}
			}
		}
	}
}

class Node
{
	public int Id { get; private set; }
	public List<Node> Children = new List<Node>();
	
	public Node (int id)
	{
		this.Id = id;
	}
}