84 lines
2.3 KiB
Java

package com.baeldung.avltree;
import org.junit.Assert;
import org.junit.Test;
public class AVLTreeUnitTest {
@Test
public void givenEmptyTree_whenHeightCalled_shouldReturnMinus1() {
AVLTree tree = new AVLTree();
Assert.assertEquals(-1, tree.height());
}
@Test
public void givenEmptyTree_whenInsertCalled_heightShouldBeZero() {
AVLTree tree = new AVLTree();
tree.insert(1);
Assert.assertEquals(0, tree.height());
}
@Test
public void givenEmptyTree_whenInsertCalled_treeShouldBeAvl() {
AVLTree tree = new AVLTree();
tree.insert(1);
Assert.assertTrue(isAVL(tree));
}
@Test
public void givenSampleTree_whenInsertCalled_treeShouldBeAvl() {
AVLTree tree = getSampleAVLTree();
int newKey = 11;
tree.insert(newKey);
Assert.assertTrue(isAVL(tree));
}
@Test
public void givenSampleTree_whenFindExistingKeyCalled_shouldReturnMatchedNode() {
AVLTree tree = getSampleAVLTree();
int existingKey = 2;
AVLTree.Node result = tree.find(existingKey);
Assert.assertEquals(result.key, existingKey);
}
@Test
public void givenSampleTree_whenFindNotExistingKeyCalled_shouldReturnNull() {
AVLTree tree = getSampleAVLTree();
int notExistingKey = 11;
AVLTree.Node result = tree.find(notExistingKey);
Assert.assertNull(result);
}
@Test
public void givenEmptyTree_whenDeleteCalled_treeShouldBeAvl() {
AVLTree tree = new AVLTree();
tree.delete(1);
Assert.assertTrue(isAVL(tree));
}
@Test
public void givenSampleTree_whenDeleteCalled_treeShouldBeAvl() {
AVLTree tree = getSampleAVLTree();
tree.delete(1);
Assert.assertTrue(isAVL(tree, tree.getRoot()));
}
private boolean isAVL(AVLTree tree) {
return isAVL(tree, tree.getRoot());
}
private boolean isAVL(AVLTree tree, AVLTree.Node node) {
if ( node == null )
return true;
int balance = tree.getBalance(node);
return (balance <= 1 && balance >= -1) && isAVL(tree, node.left) && isAVL(tree, node.right);
}
private AVLTree getSampleAVLTree() {
AVLTree avlTree = new AVLTree();
for (int i = 0; i < 10; i++)
avlTree.insert(i);
return avlTree;
}
}