public UnionFind(Collection<E> values) {
this.sizes = new HashMap<E, Integer>();
Integer one = Integer.valueOf(1);
for (E elt : values) {
elt.setUnionFindParent(elt);
sizes.put(elt, one);
}
}
public void union(E value0, E value1) {
E repr0 = findRepresentative(value0);
E repr1 = findRepresentative(value1);
if (repr0 != repr1) {
int size0 = sizes.get(repr0);
int size1 = sizes.get(repr1);
if (size0 < size1) {
sizes.remove(repr0);
repr0.setUnionFindParent(repr1);
value0.setUnionFindParent(repr1);
sizes.put(repr1, size0 + size1);
} else {
sizes.remove(repr1);
repr1.setUnionFindParent(repr0);
value1.setUnionFindParent(repr0);
sizes.put(repr0, size0 + size1);
}
}
}
public E findRepresentative(E value) {
E parent = value.getUnionFindParent();
if (parent == value) {
return value;
} else {
parent = findRepresentative(parent);
value.setUnionFindParent(parent);
return parent;
}
}
