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: Memory Limit Exceeded)

#include <stdio.h>
#define MAX 100000
#define WHITE 0
#define GRAY 1
#define BLACK 2
long int color[MAX];
long int memo[MAX];
long int v[MAX][MAX/100];

int dfs(long int u, long int t) {
   long int stack[MAX];
   long int i = 0;
   long int j;
   int judge = 0;
   stack[0] = u;
   color[u] = GRAY;
   while (stack[0] != -1) {
	  u = stack[i];
	  judge = 0;
	  if (memo[u] != 0) {
		 for (j = 0; j < memo[u]; ++j) {
			if (color[v[u][j]] == WHITE) {
			   color[v[u][j]] = GRAY;
			   stack[++i] = v[u][j];
			   if (v[u][j] == t)
				  return 1;
			   judge = 1;
			}
		 }
	  }
	  if (judge == 0) {
		 stack[i] = -1;
		 color[u] = BLACK;
		 --i;
	  }
   }
   return 0;
}

int CC(long int s, long int t, int n) {
   long int i;
   for (i = 0; i < n; ++i) {
	  color[i] = WHITE;
   }
   return dfs(s, t);
}

int main() {
   long int ans[MAX];
   long int n, m, q, s, t;
   long int vs, vt;
   long int i;

   scanf("%ld %ld", &n, &m);
   for (i = 0; i < n; ++i) {
	  memo[i] = 0;
	  v[i][0] = -1;
   }
   for (i = 0; i < m; ++i) {
	  scanf("%ld %ld", &vs, &vt);
	  v[vs][memo[vs]] = vt;
	  v[vt][memo[vt]] = vs;
	  ++memo[vs];
	  ++memo[vt];
   }

   scanf("%d", &q);
   for (i = 0; i < q; ++i) {
	  scanf("%ld %ld", &s, &t);
	  ans[i] = CC(s, t, n);
   }
   for (i = 0; i < q; ++i) {
	  if (ans[i] == 1)
		 printf("yes\n");
	  else
		 printf("no\n");
   }
   return 0;
}