public static void Main(string[] args)
{
int N = StdIn.ReadInt();
WeightedQuickUnionPathCompressionUF uf = new WeightedQuickUnionPathCompressionUF(N);
// read in a sequence of pairs of integers (each in the range 0 to N-1),
// calling find() for each pair: If the members of the pair are not already
// call union() and print the pair.
while (!StdIn.IsEmpty())
{
int p = StdIn.ReadInt();
int q = StdIn.ReadInt();
if (uf.Connected(p, q))
{
continue;
}
uf.Union(p, q);
Console.WriteLine(p + " " + q);
}
Console.WriteLine(uf.Count + " components");
}
public Percolation(int n)
{
this.n = n;
this.openMatrix = new bool[n][];
uf = new WeightedQuickUnionPathCompressionUF(n * n + 2);
this.top = n * n;
this.last = n * n + 1;
for (int i = 1; i <= n; i++)
{
uf.Union(this.top, this.toOneDimension(1, i));
uf.Union(this.last, this.toOneDimension(n, i));
}
}// create n-by-n grid, with all sites blocked