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 C (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
#define MAX_N 100000
#define MAX_M 100000
 
typedef struct EDGE {
    int to;
    struct EDGE *next;
} edge;
 
int buff_size;
edge buff[MAX_M + MAX_M];
edge *adj[MAX_N];
 
void init(int n, int m) {
    int i;
    for(i = 0; i < n; ++i) {
        adj[i] = NULL;
    }
    for(i = 0; i < m; ++i) {
        buff[i].next = NULL;
    }
    buff_size = 0;
}
 
edge *new_edge() {
    return buff + buff_size++;
}
 
void add_edge(int u, int v) {
    edge *e = new_edge();
    e->to = v;
    e->next = adj[u];
    adj[u] = e;
}
 
int head, tail;
int queue[MAX_N];
 
void enqueue(int data) {
    queue[tail++] = data;
}
 
int dequeue() {
    return queue[head++];
}
 
int empty() {
    return head == tail;
}
 
void clear() {
    head = tail = 0;
}
 
int next_label;
int label[MAX_N];
 
void bfs(int v) {
    edge *e;
 
    clear();
    enqueue(v);
 
    label[v] = next_label;
    while(!empty()) {
        const int v = dequeue();
        for(e = adj[v]; e != NULL; e = e->next) {
            if(label[e->to] == -1) {
                label[e->to] = next_label;
                enqueue(e->to);
            }
        }
    }
    ++next_label;
}
 
int main() {
    int n, m, q;
    int u, v;
    int s, t;
    int i;
 
    scanf("%d %d", &n, &m);
    init(n, m);
 
    for(i = 0; i < m; ++i) {
        scanf("%d %d", &u, &v);
        add_edge(u, v);
        add_edge(v, u);
    }
 
    memset(label, -1, sizeof(label));
    for(i = 0; i < n; ++i) {
        if(label[i] == -1) bfs(i);
    }
 
    scanf("%d", &q);
    while(q--) {
        scanf("%d %d", &s, &t);
        puts(label[s] == label[t] ? "yes" : "no");
    }
 
    return EXIT_SUCCESS;
}