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: Runtime Error)

#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];
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;
}