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 JAVA (judge verdict: Memory Limit Exceeded)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] str = br.readLine().split(" ");
		int n = Integer.parseInt(str[0]);
		int m = Integer.parseInt(str[1]);
		
		short[][] a = new short[n][m+1];
		
		//LinkedList<Integer>[] s = new LinkedList[n];
		short u, v;
		
		for(int i = 0; i < m; i++) {
			str = br.readLine().split(" ");
			u = Short.parseShort(str[0]);
			v = Short.parseShort(str[1]);
			
			a[u][0] += 1;
			a[u][a[u][0]] = v;
			a[v][0] += 1;
			a[v][a[v][0]] = u;
		}
		
		
		int q = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();
		
		short[] st = new short[n*n]; // stack
		int p = 0; // stack pointer
		question: for(int i = 0; i < q; i++){
			p = 0;
			str = br.readLine().split(" ");
			boolean[] d = new boolean[n]; 
			st[p] = Short.parseShort(str[0]); // first node
			short frid = Short.parseShort(str[1]); // friend id
			if(st[p] == frid){
				sb.append("yes\n");
				continue question;
			}
			while(p >= 0){
				int pn = st[p]; // present node
				if(d[pn] == false){
					d[pn] = true;
				}
				
				for(int j = a[pn][0]; j > 0; --j){
					if(d[a[pn][j]] == false){
						if(a[pn][j] == frid){
							sb.append("yes\n");
							continue question;
						}
						// push the adjacent nodes
						p += 1;
						st[p] = a[pn][j];
					}
				}

				if(st[p] == pn){
					// pop 
					p -= 1;
				}
			}
			sb.append("no\n");
		}
		
		System.out.print(sb);
	}

}