Merge pull request #8 from eugenp/master

sync up

algorithms-miscellaneous-4/src/main/java/com/baeldung/algorithms/smallestinteger/SmallestMissingPositiveInteger.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.smallestinteger;
+
+import java.util.Arrays;
+
+public class SmallestMissingPositiveInteger {
+    public static int searchInSortedArray(int[] input) {
+        for (int i = 0; i < input.length; i++) {
+            if (i != input[i]) {
+                return i;
+            }
+        }
+
+        return input.length;
+    }
+
+    public static int searchInUnsortedArraySortingFirst(int[] input) {
+        Arrays.sort(input);
+        return searchInSortedArray(input);
+    }
+
+    public static int searchInUnsortedArrayBooleanArray(int[] input) {
+        boolean[] flags = new boolean[input.length];
+        for (int number : input) {
+            if (number < flags.length) {
+                flags[number] = true;
+            }
+        }
+
+        for (int i = 0; i < flags.length; i++) {
+            if (!flags[i]) {
+                return i;
+            }
+        }
+
+        return flags.length;
+    }
+}

algorithms-miscellaneous-4/src/test/java/com/baeldung/algorithms/smallestinteger/SmallestMissingPositiveIntegerUnitTest.java

@@ -0,0 +1,88 @@
+package com.baeldung.algorithms.smallestinteger;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SmallestMissingPositiveIntegerUnitTest {
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInSortedArray_thenThree() {
+        int[] input = new int[] {0, 1, 2, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInSortedArray_thenOne() {
+        int[] input = new int[] {0, 2, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInSortedArray_thenArrayLength() {
+        int[] input = new int[] {0, 1, 2, 3, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInUnsortedArraySortingFirst_thenThree() {
+        int[] input = new int[] {1, 4, 0, 5, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInUnsortedArraySortingFirst_thenOne() {
+        int[] input = new int[] {4, 2, 0, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInUnsortedArraySortingFirst_thenArrayLength() {
+        int[] input = new int[] {4, 5, 1, 3, 0, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInUnsortedArrayBooleanArray_thenThree() {
+        int[] input = new int[] {1, 4, 0, 5, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInUnsortedArrayBooleanArray_thenOne() {
+        int[] input = new int[] {4, 2, 0, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInUnsortedArrayBooleanArray_thenArrayLength() {
+        int[] input = new int[] {4, 5, 1, 3, 0, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/binarygap/BinaryGap.java

@@ -0,0 +1,17 @@
+package com.baeldung.algorithms.binarygap;
+
+public class BinaryGap {
+    static int calculateBinaryGap(int n) {
+        return calculateBinaryGap(n >>> Integer.numberOfTrailingZeros(n), 0, 0);
+    }
+
+    static int calculateBinaryGap(int n, int current, int maximum) {
+        if (n == 0) {
+            return maximum;
+        } else if ((n & 1) == 0) {
+            return calculateBinaryGap(n >>> 1, current + 1, maximum);
+        } else {
+            return calculateBinaryGap(n >>> 1, 0, Math.max(maximum, current));
+        }
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/binarygap/BinaryGapUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.binarygap;
+
+import static com.baeldung.algorithms.binarygap.BinaryGap.calculateBinaryGap;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class BinaryGapUnitTest {
+
+    @Test public void givenNoOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(63);
+        assertEquals(0, result);
+    }
+
+    @Test public void givenTrailingZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(40);
+        assertEquals(1, result);
+    }
+
+    @Test public void givenSingleOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(9);
+        assertEquals(2, result);
+    }
+
+    @Test public void givenMultipleOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(145);
+        assertEquals(3, result);
+    }
+
+}

core-java-modules/README.md

@@ -5,6 +5,5 @@ This module contains modules about core Java
 ## Relevant articles:
 
 - [Multi-Module Maven Application with Java Modules](https://www.baeldung.com/maven-multi-module-project-java-jpms)
-- [Guide to Java FileChannel](https://www.baeldung.com/java-filechannel)
 - [Understanding the NumberFormatException in Java](https://www.baeldung.com/java-number-format-exception)
 - [Will an Error Be Caught by Catch Block in Java?](https://www.baeldung.com/java-error-catch)

core-java-modules/core-java-9-improvements/README.md

@@ -0,0 +1,17 @@
+## Core Java 9
+
+This module contains articles about the improvements to core Java features introduced with Java 9.
+
+### Relevant Articles:
+
+- [New Stream Collectors in Java 9](http://www.baeldung.com/java9-stream-collectors)
+- [Java 9 Optional API Additions](https://www.baeldung.com/java-9-optional)
+- [Java 9 Convenience Factory Methods for Collections](https://www.baeldung.com/java-9-collections-factory-methods)
+- [Java 9 Stream API Improvements](https://www.baeldung.com/java-9-stream-api)
+- [Java 9 java.util.Objects Additions](https://www.baeldung.com/java-9-objects-new)
+- [Java 9 CompletableFuture API Improvements](https://www.baeldung.com/java-9-completablefuture)
+
+#### Relevant articles not in this module:
+
+- [Java 9 Process API Improvements](https://www.baeldung.com/java-9-process-api) (see the [core-java-os](/core-java-os) module)
+

core-java-modules/core-java-9-improvements/pom.xml

@@ -0,0 +1,73 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-9</artifactId>
+    <version>0.2-SNAPSHOT</version>
+    <name>core-java-9</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.jayway.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${awaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-9</finalName>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <pluginRepositories>
+        <pluginRepository>
+            <id>apache.snapshots</id>
+            <url>http://repository.apache.org/snapshots/</url>
+        </pluginRepository>
+    </pluginRepositories>
+
+    <properties>
+        <!-- testing -->
+        <assertj.version>3.10.0</assertj.version>
+        <junit.platform.version>1.2.0</junit.platform.version>
+        <awaitility.version>1.7.0</awaitility.version>
+        <maven.compiler.source>1.9</maven.compiler.source>
+        <maven.compiler.target>1.9</maven.compiler.target>
+        <guava.version>25.1-jre</guava.version>
+    </properties>
+
+</project>

core-java-modules/core-java-9-jigsaw/README.md

@@ -0,0 +1,11 @@
+## Core Java 9
+
+This module contains articles about Project Jigsaw and the Java Platform Module System (JPMS), introduced with Java 9.
+
+### Relevant Articles:
+
+- [Introduction to Project Jigsaw](http://www.baeldung.com/project-jigsaw-java-modularity)
+- [A Guide to Java 9 Modularity](https://www.baeldung.com/java-9-modularity)
+- [Java 9 java.lang.Module API](https://www.baeldung.com/java-9-module-api)
+
+

core-java-modules/core-java-9-jigsaw/pom.xml

@@ -0,0 +1,35 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-9-jigsaw</artifactId>
+    <version>0.2-SNAPSHOT</version>
+    <name>core-java-9</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../</relativePath>
+    </parent>
+
+    <build>
+        <finalName>core-java-9-jigsaw</finalName>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source>1.9</maven.compiler.source>
+        <maven.compiler.target>1.9</maven.compiler.target>
+    </properties>
+
+</project>