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 Rust (judge verdict: Accepted)

use std::io::Read;
// use std::collections::VecDeque;

fn main() {
    let mut buf = String::new();
    std::io::stdin().read_to_string(&mut buf).unwrap();

    let answer = solve(&buf);

    println!("{}", answer);
}

fn solve(input: &str) -> String {
    let mut iterator = input.split_whitespace();

    let n: usize = iterator.next().unwrap().parse().unwrap();
    let m: usize = iterator.next().unwrap().parse().unwrap();

    let mut graph: Vec<Vec<usize>> = vec![Vec::new(); n];
    for _ in 0..m {
        let s: usize = iterator.next().unwrap().parse().unwrap();
        let t: usize = iterator.next().unwrap().parse().unwrap();
        graph[s].push(t);
        graph[t].push(s);
    }

    let mut colors: Vec<usize> = vec![0; n];
    let mut color = 1;
    for i in 0..n {
        if colors[i] != 0 {
            continue;
        }

        // bfs
        // let mut queue: VecDeque<usize> = VecDeque::new();
        // queue.push_back(i);
        // while !queue.is_empty() {
        //     let node = queue.pop_front().unwrap();
        //     colors[node] = color;
        //     for linked in graph[node].iter() {
        //         if colors[*linked] == 0 {
        //             queue.push_back(*linked);
        //         }
        //     }
        // }

        // dfs
        let mut stack: Vec<usize> = Vec::new();
        stack.push(i);
        while !stack.is_empty() {
            let node = stack.pop().unwrap();
            colors[node] = color;
            for linked in graph[node].iter() {
                if colors[*linked] == 0 {
                    stack.push(*linked);
                }
            }
        }

        color += 1;
    }

    let mut result = String::new();

    let q: usize = iterator.next().unwrap().parse().unwrap();
    for _ in 0..q {
        let s: usize = iterator.next().unwrap().parse().unwrap();
        let t: usize = iterator.next().unwrap().parse().unwrap();
        if colors[s] == colors[t] {
            result.push_str("yes\n");
        } else {
            result.push_str("no\n");
        }
    }

    return result.trim().to_string();
}