feat: adds lesson 08 content

lesson_08/README.md

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+# Lesson 08
+
+## Homework
+
+* Complete three [coding interview questions](#coding-interview-questions).
+
+## Coding Interview questions
+
+* Find a cycle in a LinkedList.
+* Complete function that returns whether an array of elements contains a duplicate.
+* Write a function that returns the maximum path of a tree.
+

lesson_08/collections/.gitattributes

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+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat text eol=crlf
+

lesson_08/collections/.gitignore

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+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build

lesson_08/collections/collections_app/build.gradle.kts

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+plugins {
+ // Apply the application plugin to add support for building a CLI application in Java.
+ application
+ eclipse
+ id("com.diffplug.spotless") version "6.25.0"
+ id("org.springframework.boot") version "3.2.2"
+ id("com.adarshr.test-logger") version "4.0.0"
+}
+
+apply(plugin = "io.spring.dependency-management")
+
+repositories {
+ // Use Maven Central for resolving dependencies.
+ mavenCentral()
+}
+
+dependencies {
+ // Use JUnit Jupiter for testing.
+ testImplementation("com.codedifferently.instructional:instructional-lib")
+ testImplementation("org.junit.jupiter:junit-jupiter:5.9.1")
+ testImplementation("org.springframework.boot:spring-boot-starter-test")
+ testImplementation("org.assertj:assertj-core:3.25.1")
+ testImplementation("at.favre.lib:bcrypt:0.10.2")
+
+ // This dependency is used by the application.
+ implementation("com.codedifferently.instructional:instructional-lib")
+ implementation("com.google.guava:guava:31.1-jre")
+ implementation("com.google.code.gson:gson:2.10.1")
+ implementation("org.projectlombok:lombok:1.18.30")
+ implementation("org.springframework.boot:spring-boot-starter")
+}
+
+application {
+ // Define the main class for the application.
+ mainClass.set("com.codedifferently.lesson8.Lesson8")
+}
+
+tasks.named<Test>("test") {
+ // Use JUnit Platform for unit tests.
+ useJUnitPlatform()
+}
+
+
+configure<com.diffplug.gradle.spotless.SpotlessExtension> {
+
+ format("misc", {
+ // define the files to apply `misc` to
+ target("*.gradle", ".gitattributes", ".gitignore")
+
+ // define the steps to apply to those files
+ trimTrailingWhitespace()
+ indentWithTabs() // or spaces. Takes an integer argument if you don't like 4
+ endWithNewline()
+ })
+
+ java {
+ // don't need to set target, it is inferred from java
+
+ // apply a specific flavor of google-java-format
+ googleJavaFormat()
+ // fix formatting of type annotations
+ formatAnnotations()
+ }
+}

lesson_08/collections/collections_app/src/main/java/com/codedifferently/lesson8/Lesson8.java

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+package com.codedifferently.lesson8;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@SpringBootApplication(scanBasePackages = "com.codedifferently")
+public class Lesson8 {
+
+ public static void main(String[] args) {
+ var application = new SpringApplication(Lesson8.class);
+ application.run(args);
+ }
+
+ public static boolean containsCycle(LinkedListNode head) {
+ return false;
+ }
+
+ public static int getMaximumBinaryTreeHeight(BinaryTreeNode root) {
+ return -1;
+ }
+
+ public static boolean containsDuplicates(String[] values) {
+ return false;
+ }
+
+ public static class LinkedListNode {
+ public LinkedListNode next;
+ public int val;
+
+ public LinkedListNode(int val) {
+ this.val = val;
+ }
+ }
+
+ public static class BinaryTreeNode {
+ public int val;
+ public BinaryTreeNode left;
+ public BinaryTreeNode right;
+
+ public BinaryTreeNode(int val) {
+ this.val = val;
+ }
+ }
+}

lesson_08/collections/collections_app/src/test/java/com/codedifferently/lesson8/Lesson8Test.java

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+package com.codedifferently.lesson8;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static com.codedifferently.lesson8.Lesson8.LinkedListNode;
+import static com.codedifferently.lesson8.Lesson8.BinaryTreeNode;
+
+import org.junit.jupiter.api.Test;
+
+class Lesson8Test {
+
+ @Test
+ void testCanVote() {
+ assertThat(new Lesson8()).isNotNull();
+ }
+
+ @Test
+ void testContainsCycle() {
+ LinkedListNode node1 = new LinkedListNode(1);
+ LinkedListNode node2 = new LinkedListNode(2);
+ LinkedListNode node3 = new LinkedListNode(3);
+ node1.next = node2;
+ node2.next = node3;
+ node3.next = node1;
+
+ boolean result = Lesson8.containsCycle(node1);
+
+ assertThat(result).isTrue();
+ }
+
+ @Test
+ void testGetMaximumBinaryTreeHeight() {
+ BinaryTreeNode root = new BinaryTreeNode(1);
+ BinaryTreeNode left = new BinaryTreeNode(2);
+ BinaryTreeNode right = new BinaryTreeNode(3);
+ root.left = left;
+ root.right = right;
+ left.left = new BinaryTreeNode(4);
+ left.right = new BinaryTreeNode(5);
+ right.left = new BinaryTreeNode(6);
+
+ int result = Lesson8.getMaximumBinaryTreeHeight(root);
+
+ assertThat(result).isEqualTo(3);
+ }
+
+ @Test
+ void testContainsDuplicates() {
+ String[] values = {"apple", "banana", "cherry", "apple"};
+
+ boolean result = Lesson8.containsDuplicates(values);
+
+ assertThat(result).isTrue();
+ }
+}

lesson_08/collections/gradle/wrapper/gradle-wrapper.properties

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+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.2-bin.zip
+networkTimeout=10000
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists