Check Trees are Identical

package org.wesome.dsalgo;

import lombok.Data;

import java.util.Objects;

public class BinarySearchTree {
    Node root;

    boolean identicalTrees(Node a, Node b) {
        /* 1. both empty */
        if (Objects.isNull(a) && Objects.isNull(b)) {
            return true;
        }

        /* 2. both non-empty -> compare them */
        if (Objects.nonNull(a) && Objects.nonNull(b)) {
            return (a.data == b.data && identicalTrees(a.left, b.left) && identicalTrees(a.right, b.right));
        }

        /* 3. one empty, one not -> false */
        return false;
    }

    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;

public class BinarySearchTreeTest {
    @Test
    void identicalTreesTest() {
        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);
        Assertions.assertTrue(binarySearchTree.identicalTrees(binarySearchTree.root, binarySearchTree.root));
    }
}
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()
}

 

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