Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const MAX = 100000

type Queue struct {
	head      int
	tail      int
	container [MAX]int
}

func (q *Queue) push(n int) {
	q.container[q.tail] = n
	q.tail = (q.tail + 1) % MAX
}

func (q *Queue) pop() int {
	res := q.container[q.head]
	q.head = (q.head + 1) % MAX
	return res
}

func (q *Queue) isEmpty() bool {
	return q.head == q.tail
}

var sc = bufio.NewScanner(os.Stdin)
var route [][]int
var SEEN [MAX]bool
var GROUP [MAX]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func bfs(start, group int) {
	que := Queue{}
	que.push(start)

	for !que.isEmpty() {
		id := que.pop()

		if SEEN[id] {
			continue
		}
		SEEN[id] = true
		GROUP[id] = group

		for _, next := range route[id] {
			que.push(next)
		}
	}
}

func main() {
	n, m := scanInt(), scanInt()
	route = make([][]int, n)
	for i := 0; i < m; i++ {
		s, t := scanInt(), scanInt()
		route[s] = append(route[s], t)
		route[t] = append(route[t], s)
	}

	for i := 0; i < n; i++ {
		if !SEEN[i] {
			bfs(i, i+1)
		}
	}

	w := bufio.NewWriter(os.Stdout)
	q := scanInt()
	for i := 0; i < q; i++ {
		s, t := scanInt(), scanInt()
		if GROUP[s] == GROUP[t] {
			fmt.Fprintln(w, "yes")
		} else {
			fmt.Fprintln(w, "no")
		}
	}
	w.Flush()
}

Python: def bfs(graph, start, goal, connection):
    visited = {start: None}
    unvisited = [start]
    while unvisited:
        now = unvisited[0]
        if now == goal or connection[now][goal] == 1:
            connection[start][goal] = 1
            return "yes"
        unvisited = unvisited[1:]
        for next in graph[now][1:]:
            if not (next in visited):
                unvisited.append(next)
                visited[next] = now
    return "no"

n, m = map(int, input().split())
g = [[i] for i in range(n)]
c = [[0 for i in range(n)] for i in range(n)]

for i in range(m):
    inp = list(map(int, input().split()))
    g[inp[0]].append(inp[1])
    g[inp[1]].append(inp[0])

q = int(input())

for i in range(q):
    s, t = map(int, input().split())
    print(bfs(g, s, t, c))

Python: from collections import deque

def bfs(graph, start):
    visited = {start: None}
    unvisited = deque()
    unvisited.append(start)
    while unvisited:
        now = unvisited.popleft()
        for next in graph[now]:
            if not (next in visited):
                unvisited.append(next)
                visited[next] = now
    for key in visited.keys():
        graph[key].update(visited.keys())

n, m = map(int, input().split())
g = [set() for i in range(n)]

for i in range(m):
    a, b = map(int, input().split())
    g[a].add(b)
    g[b].add(a)

q = int(input())

for i in range(q):
    s, t = map(int, input().split())
    if t in g[s]:
        print("yes")
    else:
        bfs(g, s)
        if t in g[s]:
            print("yes")
        else:
            print("no")

Python: import sys
input = sys.stdin.readline
from operator import itemgetter
sys.setrecursionlimit(10000000)
from collections import deque

def main():
    n, m = map(int, input().strip().split())
    nei = [[] for _ in range(n)]
    for _ in range(m):
        s, t = map(int, input().strip().split())
        nei[s].append(t)
        nei[t].append(s)

    nodes = [-1] * n
    color = 1
    for i in range(n):
        if nodes[i] > 0:
            continue
        d = deque()
        d.append(i)
        # print(nei)
        while len(d) != 0:
            k = d.popleft()
            nodes[k] = color
            for j in nei[k]:
                if nodes[j] == -1:
                    d.append(j)
            # print(len(d))
        color += 1

    q = int(input().strip())
    for _ in range(q):
        s, t = map(int, input().strip().split())
        if nodes[s] == nodes[t]:
            print('yes')
        else:
            print('no')

if __name__ == '__main__':
    main()

Python: def DFS(s):
    flag[s] = 1
    F[group] += [s]
    for i in range(n):
        if G[s][i] == 1:
            if flag[i] == 0:
                DFS(i)
 

n, m = map(int, input().split())
G = [[0 for i in range(n)] for j in range(n)]
for i in range(m):
    s, t = map(int, input().split())
    G[s][t] = 1
    G[t][s] = 1

F = []
flag = [0 for i in range(n)]
group = 0
for i in range(n):
    if flag[i] == 0:
        F.append([])
        DFS(i)
        group += 1

q = int(input())
ans = ["no" for i in range(q)]
for i in range(q):
    s, t = map(int, input().split())
    for friends in F:
        if s in friends and t in friends:
            ans[i] = "yes"

for i in range(q):
    print(ans[i])

Python: n,m = map(int,raw_input().strip().split(' '))
graph = [[] for i in range(n)]
for i in range(m):
    s,t = map(int,raw_input().strip().split(' '))
    graph[s].append(t)
    graph[t].append(s)
 
color = {}
c = 0
for i in range(n):
    if not i in color:
        que = [i]
        color[i] = c
        if len(que) > 0:
         for j in range (n):
            u = que[0]
            for v in graph[u]:
                if not v in color:
                    color[v] = c
                    que.append(v)
            del que[0]
        c += 1

Python: from collections import deque

n, m = map(int, input().split())
g = [set() for _ in range(n)]
gids = [0] * n

while m:
    s, t = map(int, input().split())
    g[s].add(t)
    g[t].add(s)
    m -= 1


def search(s, gid):
    global g, gids
    queue = deque()
    queue.append(s)
    visited = [0] * n
    visited[s] = 1
    gids[s] = gid

    while queue:
        i = queue.popleft()
        for f in g[i]:
            if not visited[f]:
                visited[f] = 1
                gids[f] = gid
                queue.append(f)


gid = 1
for i in range(n):
    if gids[i]:
        continue
    search(i, gid)
    gid += 1

q = int(input())
while q:
    s, t = map(int, input().split())
    gs, gt = gids[s], gids[t]
    print('yes' if gs and gt and gs == gt else 'no')
    q -= 1

Python: #coding: utf-8
n, m = map(int,input().split())
List = [[] for i in range(n)]

for i in range(m):
    s,t = map(int,input().split())
    List[s].append(t)
    List[t].append(s)


def search(a,target):
    if a == target:
        print("yes")
        return True
    for member in List[a]:
        if color[member] == "white":
            color[member] = "black"
            return search(member, target)

p = int(input())
for i in range(p):
    color = ["white" for i in range(n)]
    a, target = map(int,input().split())
    color[a] = "black"
    b = search(a, target)
    if b != True:
        print("no")

Python: # coding: UTF-8
from collections import deque
n,m = map(int,input().split())
link = [[] for _ in range(n)]
part = [-1 for _ in range(n)]
for _ in range(m):
  u,v = map(int,input().split())
  link[u].append(v)
  link[v].append(u)

searched = set()
queue = deque()
pindex = 0
for u in range(n):
  if u not in searched:
    queue.append(u)
    pindex += 1
    searched.add(u)
    while queue:
      v = queue.popleft()
      part[v] = pindex
      for w in link[v]:
        if w not in searched:
          part[w] = pindex
          queue.append(w)
          searched.add(w)

q = int(input())
answers = []
for _ in range(q):
  s,t = map(int,input().split())
  if part[s] == part[t]:
    answers.append("yes")
  else:
    answers.append("no")

for answer in answers:
  print(answer)