quick-find solution of connectivity problem

👍 g++ program11.cpp && ./a.out
3 4
 3 4
4 9
 4 9
8 0
 8 0
2 3
 2 3
5 6
 5 6
2 9
5 9
 5 9
7 3
 7 3
4 8
 4 8
5 6
0 2
6 1
 6 1

👍 cat program11.in
3 4
4 9
8 0
2 3
5 6
2 9
5 9
7 3
4 8
5 6
0 2
6 1

👍 ./a.out < program11.in
 3 4
 4 9
 8 0
 2 3
 5 6
 5 9
 7 3
 4 8
 6 1


👍 cat program11.cpp 
#include <iostream>
using namespace std;
static const int N = 10000;
int main() {
  int i, p, q, id[N];
  for (i = 0; i < N; i++) id[i] = i;
  while (cin >> p >> q) {
    int t = id[p];
    if (t == id[q]) continue;
    for (i = 0; i < N; i++)
      if (id[i] == t) id[i] = id[q];
    cout << " " << p 
         << " " << q << endl;
  }
}

    

ch 1.3 Union-Find Algorithms p11 of