Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

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 C (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>

struct node{
	int key;
	struct node *next;
};
typedef struct node* nP;

nP List[100001], NIL;
int n, visited[100001],att;

void insert(nP head, int x){
	nP data = (nP)malloc(sizeof(struct node));
	data->key=x;
	data->next=head->next;
	head->next=data;

	return;
}

void Search(int x){
	if(visited[x])return;
	int Q[1000000],front,tail, i;
	nP tmp;
	front=tail=0;
	Q[tail]=x;	++tail;

	while(front!=tail){
		x=Q[front];	++front;
		visited[x]=att;
		for(tmp=List[x]->next; tmp!=NIL; tmp=tmp->next){
			if(visited[tmp->key]==att)continue;
			Q[tail]=tmp->key;	++tail;
		}
	}

	return;
}

int main(){
	int i,j,m,q,s,t;	scanf("%d%d",&n,&m);
	nP tmp;

	NIL=(nP)malloc(sizeof(struct node));
	for(i=0;i<n;i++)List[i]=(nP)malloc(sizeof(struct node));
	NIL->key=-1;
	for(i=0;i<n;i++)List[i]->next=NIL;

	for(i=0;i<m;i++){
		scanf("%d%d",&s,&t);
		insert(List[s],t);
		insert(List[t],s);
	}

	att=0;
	for(i=0;i<n;i++){
		++att;
		Search(i);
	}

	scanf("%d",&q);
	for(i=1;i<=q;i++){
		scanf("%d%d",&s,&t);
		if(visited[s]==visited[t])printf("yes\n");
		else printf("no\n");
	}


	return 0;
}