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 <iostream>
#include <vector>
#include <stack>
using namespace std;
static const int MAX_N = 100010;
static const int NIL = -1;

vector<int> G[MAX_N];
int color[MAX_N];

void bfs(int u, int id) {
  stack<int> s;
  s.push(u);
  color[u] = id;
  while (!s.empty()) {
    int f = s.top(); s.pop();
    for (int i = 0; i < G[f].size(); ++i) {
      int v = G[f][i];
      if (color[v] == NIL) {
        color[v] = id;
        s.push(v);
      }
    }
  }
}

int main() {
  int n, m, s, t, q;

  cin >> n >> m;

  for (int i = 0; i < m; ++i) {
    cin >> s >> t;
    G[s].push_back(t);
    G[t].push_back(s);
  }

  for (int i = 0; i < n; ++i) {
    color[i] = NIL;
  }

  int id = 1;
  for (int u = 0; u < n; ++u) {
    if (color[u] == NIL) {
      bfs(u, id++);
    }
  }

  cin >> q;
  for (int i = 0; i < q; ++i) {
    cin >> s >> t;
    if (color[s] == color[t]) {
      cout << "yes\n";
    } else {
      cout << "no\n";
    }
  }
  
  return 0;
}