/**
* Unions sets, which contain vertices "a" and "b" Union is always performed as merging "B" into
* "A"
*
* @param a number of a node "a"
* @param b number of a node "b"
* @return number of a representative of the merged component
*/
public int union(int a, int b) {
DisjointSet.Node repA = nodes[find(a)];
DisjointSet.Node repB = nodes[find(b)];
repB.parent = repA;
return repA.id;
}
/**
* Performs compression of the path
*
* @param a
* @param rootId
*/
private void repair(int a, int rootId) {
DisjointSet.Node curr = nodes[a];
while (curr.id != rootId) {
DisjointSet.Node tmp = curr.parent;
curr.parent = nodes[rootId];
curr = tmp;
}
}