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 Scala (judge verdict: Accepted)

import scala.io.StdIn.{readInt, readLine};
import scala.collection.immutable.Queue;
object Main {
    def main(args: Array[String]): Unit = {
        val input1 = readLine.split(" ").map(_.toInt);
        val users = input1(0);
        val friends = input1(1);
        val ig = new IntGraph(users);
        (0 until friends).foreach { i => 
            readLine.split(" ").map(_.toInt) match {
                case Array(src, dst) => ig.add(src, dst);
                case _ => ();
            }
        }
        ig.buildConnectionList();
        (0 until readInt).foreach { i => 
            readLine.split(" ").map(_.toInt) match {
                case Array(src, dst) => if (ig.connected(src, dst)) println("yes") else println("no");
                case _ => ();
            }
        }
    }
}

class IntGraph(size: Int) {
    val matrix: Array[List[Int]] = new Array[List[Int]](size).map( e => Nil);
    val cList = new Array[Int](size).map( e => -1);
    def add(src: Int, dst: Int): Unit = {
        matrix(src) = dst :: matrix(src);
        matrix(dst) = src :: matrix(dst);
    }
    
    def buildConnectionList(): Unit = {
        def _buildConnectionList(que: Queue[Int], group: Int): Queue[Int] = {
            que.dequeueOption match {
                case None => que;
                case Some((src, restQue)) => {
                    val newQue = matrix(src).filter(dst => cList(dst) == -1).foldLeft(restQue) { (tmpQue, dst) =>
                        cList(dst) = group;
                        tmpQue.enqueue(dst);
                    }
                    _buildConnectionList(newQue, group);
                }
            }
        }
        (0 until size).foldLeft(0) { (group, i) =>
            if (cList(i) == -1) {
                cList(i) = group;
                _buildConnectionList(Queue[Int](i), group);
                group + 1;
            } else {
                group;
            }
        }
    }
    
    def connected(src: Int, dst: Int): Boolean = cList(src) == cList(dst);
}