package org.wesome.dsalgo;
import lombok.Data;
import java.util.Objects;
public class BinarySearchTree {
Node root;
static int lowestCommonAncestor(Node node, int n1, int n2) {
if (Objects.isNull(node)) {
return -1;
}
// If both n1 and n2 are smaller than root, then LCA lies in left
if (node.data > n1 && node.data > n2) {
return lowestCommonAncestor(node.left, n1, n2);
}
// If both n1 and n2 are greater than root, then LCA lies in right
if (node.data < n1 && node.data < n2) {
return lowestCommonAncestor(node.right, n1, n2);
}
return node.data;
}
/* Inorder -> Left -> Root -> Right */
void printInOrder() {
System.out.println("print In Order");
printInOrder(root);
}
void printInOrder(Node root) {
if (Objects.isNull(root)) {
return;
}
printInOrder(root.left);
System.out.print(" " + root.data);
printInOrder(root.right);
}
void insert(int data) {
System.out.println("BinarySearchTree.insert data = " + data);
root = insert(root, data);
}
Node insert(Node root, int data) {
if (Objects.isNull(root)) {
Node tempNode = new Node(data);
return tempNode;
}
if (data > root.data) {
root.right = insert(root.right, data);
} else {
root.left = insert(root.left, data);
}
return root;
}
}
@Data
class Node {
int data;
Node left, right;
public Node(int data) {
this.data = data;
left = right = null;
}
}
package org.wesome.dsalgo;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import static org.wesome.dsalgo.BinarySearchTree.lowestCommonAncestor;
public class BinarySearchTreeTest {
@Test
void lowestCommonAncestorTest() {
BinarySearchTree binarySearchTree = new BinarySearchTree();
binarySearchTree.insert(4);
binarySearchTree.insert(2);
binarySearchTree.insert(1);
binarySearchTree.insert(3);
binarySearchTree.insert(6);
binarySearchTree.insert(5);
binarySearchTree.insert(7);
binarySearchTree.printInOrder();
Assertions.assertEquals(4, lowestCommonAncestor(binarySearchTree.root, 1, 7));
}
}
plugins {
id 'java'
id "io.freefair.lombok" version "6.2.0"
}
group = 'org.wesome'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = JavaVersion.VERSION_1_8
configurations {
compileOnly {
extendsFrom annotationProcessor
}
}
repositories {
mavenCentral()
}
dependencies {
testImplementation 'org.junit.jupiter:junit-jupiter:5.6.2'
}
test {
useJUnitPlatform()
}