/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.streams.processor.internals;
import org.junit.Test;
import java.util.HashSet;
import java.util.Set;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotEquals;
public class QuickUnionTest {
@SuppressWarnings("unchecked")
@Test
public void testUnite() {
QuickUnion<Long> qu = new QuickUnion<>();
long[] ids = {
1L, 2L, 3L, 4L, 5L
};
for (long id : ids) {
qu.add(id);
}
assertEquals(5, roots(qu, ids).size());
qu.unite(1L, 2L);
assertEquals(4, roots(qu, ids).size());
assertEquals(qu.root(1L), qu.root(2L));
qu.unite(3L, 4L);
assertEquals(3, roots(qu, ids).size());
assertEquals(qu.root(1L), qu.root(2L));
assertEquals(qu.root(3L), qu.root(4L));
qu.unite(1L, 5L);
assertEquals(2, roots(qu, ids).size());
assertEquals(qu.root(1L), qu.root(2L));
assertEquals(qu.root(2L), qu.root(5L));
assertEquals(qu.root(3L), qu.root(4L));
qu.unite(3L, 5L);
assertEquals(1, roots(qu, ids).size());
assertEquals(qu.root(1L), qu.root(2L));
assertEquals(qu.root(2L), qu.root(3L));
assertEquals(qu.root(3L), qu.root(4L));
assertEquals(qu.root(4L), qu.root(5L));
}
@Test
public void testUniteMany() {
QuickUnion<Long> qu = new QuickUnion<>();
long[] ids = {
1L, 2L, 3L, 4L, 5L
};
for (long id : ids) {
qu.add(id);
}
assertEquals(5, roots(qu, ids).size());
qu.unite(1L, 2L, 3L, 4L);
assertEquals(2, roots(qu, ids).size());
assertEquals(qu.root(1L), qu.root(2L));
assertEquals(qu.root(2L), qu.root(3L));
assertEquals(qu.root(3L), qu.root(4L));
assertNotEquals(qu.root(1L), qu.root(5L));
}
private Set<Long> roots(QuickUnion<Long> qu, long... ids) {
HashSet<Long> roots = new HashSet<>();
for (long id : ids) {
roots.add(qu.root(id));
}
return roots;
}
}