Go: // AOJ ALDS1_11_D: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_D

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var nocolor = -1

type graph struct {
	graph  [][]int
	colors []int
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func newGraph(nodeNum int) *graph {
	colors := make([]int, nodeNum)
	g := make([][]int, nodeNum)
	for i := 0; i < nodeNum; i++ {
		g[i] = []int{}
		colors[i] = nocolor
	}

	return &graph{g, colors}
}

func constructGraph(sc *bufio.Scanner) *graph {
	usersNum := nextInt(sc)
	linkNum := nextInt(sc)

	g := newGraph(usersNum)
	for i := 0; i < linkNum; i++ {
		u := nextInt(sc) // node
		l := nextInt(sc) // link node
		// edge each other
		g.graph[u] = append(g.graph[u], l)
		g.graph[l] = append(g.graph[l], u)
	}
	return g
}

func (g *graph) dfs(r, color int) {
	g.colors[r] = color

	stack := list.New()
	stack.PushFront(r)

	for stack.Len() > 0 {
		v := stack.Remove(stack.Front()).(int)
		for _, u := range g.graph[v] {
			if g.colors[u] == nocolor {
				g.colors[u] = color
				stack.PushFront(u)
			}
		}
	}
}

func (g *graph) assignColor() {
	color := 1
	for u := 0; u < len(g.graph); u++ {
		if g.colors[u] == nocolor {
			g.dfs(u, color)
			color++
		}
	}
}

func (g *graph) isLink(s, t int) bool {
	return g.colors[s] == g.colors[t]
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// construct graph and friendly colors
	g := constructGraph(sc)
	g.assignColor()

	// judge link
	q := nextInt(sc)
	for i := 0; i < q; i++ {
		s := nextInt(sc)
		t := nextInt(sc)

		if g.isLink(s, t) {
			fmt.Println("yes")
		} else {
			fmt.Println("no")
		}
	}
}

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
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

output:
yes
yes
no

"""

import sys


def assign_color():
    _color = 1
    for v in range(vertices):
        if color[v] == -1:
            graph_dfs(v, _color)
            _color += 1
    return None


def graph_dfs(vertex, _color):
    vertices_stack = list()
    vertices_stack.append(vertex)
    _color[vertex] = _color

    while vertices_stack:
        current_vertex = vertices_stack.pop()
        for v in adj_table[current_vertex]:
            if _color[v] == -1:
                _color[v] = _color
                vertices_stack.append(v)
    return None


def solve():
    for relation in relation_info:
        key, value = map(int, relation)
        adj_table[key].append(value)
        adj_table[value].append(key)

    assign_color()

    # print(adj_list)
    for question in questions:
        start, target = map(int, question)
        if color[start] == color[target]:
            print("yes")
        else:
            print("no")
    return color


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices, relations = map(int, _input[0].split())

    relation_info = map(lambda x: x.split(), _input[1:relations + 1])

    q_num = int(_input[relations + 1])
    questions = map(lambda x: x.split(), _input[relations + 2:])

    adj_table = tuple([] for _ in range(vertices))
    color = [-1] * vertices
    ans = solve()

Python: # -*- coding: utf-8 -*-
"""

"""

import sys
sys.setrecursionlimit(1000000)


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

for i in range(m):
    relation=[int(j) for j in input().split()]
    graph[relation[0]].append(relation[1])
    graph[relation[1]].append(relation[0])


check=[0 for i in range(n)]
rabel=0
stack=[]

#深さ優先探索
def dfs(graph,i):
    global stack
    global n
    global rabel

    if check[i]==0:

        #行った足跡をつける
        check[i]=rabel

        #今いる場所の情報
        now=graph[i]

        #スタックに入れる
        stack.append(now)

        #今いる場所から到達できる地点のうち、まだ行っていないとこ全部でdfs
        for j in now:
            if check[j]==0:
                dfs(graph,j)

        stack.pop()

for i in range(n):
    if check[i]==0:
        rabel+=1
        dfs(graph,i)
# print(check)



num=int(input())
for i in range(num):
    a,b=[int(j) for j in input().split()]
    if check[a]==check[b]:
        print("yes")
    else:
        print("no")

Python: def connect(s,t):
    global ct
    if color[s]!="white" or ct==1:
        return
    color[s]="grey"
    for i in fr[s]:
        if i==-1:
            continue
        elif i==t:
             ct+=1
        else:
            connect(i,t)

n,m=map(int,raw_input().split())
fr=[[-1]*n for i in xrange(n)]
for i in xrange(m):
    s,t=map(int,raw_input().split())
    fr[s][t]=t
    fr[t][s]=s
q=input()
for i in xrange(q):
    ct=0
    color=["white"]*n
    s,t=map(int,raw_input().split())
    connect(s,t)
    if ct==0:
        print('no')
    else:
        print('yes')

Python: import sys
class Union():
    def __init__(self, n):
        self.pre = [i for i in range(n)]
        self.rank = [1 for _ in range(n)]

    def union(self, a, b):
        aroot = self.find(a)
        broot = self.find(b)
        if aroot == broot:
            return
        if self.rank[aroot] < self.rank[broot]:
            aroot, broot = broot, aroot
        self.pre[broot] = self.pre[aroot]
        if self.rank[aroot] == self.rank[broot]:
            self.rank[aroot] += 1

    def find(self, n):
        while self.pre[n] != n:
            n = self.pre[n]
        return n

    def issame(self, a, b):
        if self.find(a) == self.find(b):
            return True
        return False

if __name__ == '__main__':
    m, n = map(int, sys.stdin.readline().split())
    union = Union(m)

    for _ in range(n):
        a, b = map(int, sys.stdin.readline().split())
        union.union(a, b)

    o = int(input())
    for _ in range(o):
        p, q = map(int, sys.stdin.readline().split())
        if union.issame(p, q):
            print('yes')
        else:
            print('no')

Python: def DFS(s):
    flag[s] = 1
    F[group].append(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: # -*- coding: utf-8 -*-
from collections import deque

N, M = tuple(map(int, input().split()))
adj = [[0]*(N) for _ in range(N)]

for _ in range(M):
    inp = tuple(map(int, input().split()))
    adj[inp[0]][inp[1]] = 1
    adj[inp[1]][inp[0]] = 1

unsearched = set(range(N))
colors = {n:-1 for n in range(N)}
color = -1
while len(unsearched):
    color += 1
    start = min(unsearched)
    unsearched.remove(start)
    searched = set([start])
    
    que = deque([start])
    while len(que):
        q = que.pop()
        next_ = [i for i in unsearched if adj[q][i]==1 and not (i in searched)]
        searched.update(next_)
        unsearched = unsearched.difference(searched)
        que.extendleft(next_)
    for n in searched:
        colors[n] = color
    
Q = int(input())

for i in range(Q):
    question = tuple(map(int, input().split()))
    if colors[question[0]] == colors[question[1]]:
        print("yes")        
    else:
        print("no")

Python: entry = map(int, raw_input())
n = entry[0]
m = entry[1]
A = [] * n
for i in range(m):
    entry = map(int, raw_input())
    A[entry[0]].append(entry[1])
    A[entry[1]].append(entry[0])

q = int(raw_input())
for i in range(q):
    entry = map(int, raw_input())
    if entry[1] in A[entry[0]]:
        print("yes")
    else:
        print("no")