Merge branch 'master' into contrib/booths-minimal-rotation

Author: DenizAltunkapan

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.1.0
         with:
           java-version: 21
           distribution: 'temurin'

.github/workflows/codeql.yml

@@ -24,21 +24,21 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.1.0
         with:
           java-version: 21
           distribution: 'temurin'
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.38.2
+        uses: github/codeql-action/init@v4.39.0
         with:
           languages: 'java-kotlin'
 
       - name: Build
         run: mvn --batch-mode --update-snapshots verify
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.38.2
+        uses: github/codeql-action/analyze@v4.39.0
         with:
           category: "/language:java-kotlin"
 
@@ -55,12 +55,12 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.38.2
+        uses: github/codeql-action/init@v4.39.0
         with:
           languages: 'actions'
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.38.2
+        uses: github/codeql-action/analyze@v4.39.0
         with:
           category: "/language:actions"
 ...

.github/workflows/infer.yml

@@ -18,7 +18,7 @@ jobs:
       - uses: actions/checkout@v7
 
       - name: Set up JDK
-        uses: actions/setup-java@v6.0.1
+        uses: actions/setup-java@v6.1.0
         with:
           java-version: 21
           distribution: 'temurin'

README.md

@@ -17,4 +17,4 @@ These implementations are intended for learning purposes. As such, they may be l
 Please read our [Contribution Guidelines](CONTRIBUTING.md) before you contribute to this project.
 
 ## Algorithms
-Our [directory](DIRECTORY.md) has the full list of applications.
+Our [directory](DIRECTORY.md) contains the full list of algorithms implemented in Java.

pom.xml

@@ -119,7 +119,7 @@
             <plugin>
                 <groupId>com.github.spotbugs</groupId>
                 <artifactId>spotbugs-maven-plugin</artifactId>
-                <version>4.10.4.1</version>
+                <version>4.10.5.0</version>
                 <configuration>
                     <excludeFilterFile>spotbugs-exclude.xml</excludeFilterFile>
                     <includeTests>true</includeTests>

src/main/java/com/thealgorithms/searches/ExponentialSearch.java

@@ -19,7 +19,7 @@
  * Note: This algorithm requires that the input array be sorted.
  * </p>
  */
-class ExponentialSearch implements SearchAlgorithm {
+public final class ExponentialSearch implements SearchAlgorithm {
 
     /**
      * Finds the index of the specified key in a sorted array using exponential search.
@@ -31,13 +31,13 @@ class ExponentialSearch implements SearchAlgorithm {
      */
     @Override
     public <T extends Comparable<T>> int find(T[] array, T key) {
-        if (array.length == 0) {
+        if (array == null || array.length == 0 || key == null) {
             return -1;
         }
-        if (array[0].equals(key)) {
+        if (key.compareTo(array[0]) == 0) {
             return 0;
         }
-        if (array[array.length - 1].equals(key)) {
+        if (key.compareTo(array[array.length - 1]) == 0) {
             return array.length - 1;
         }
 

src/main/java/com/thealgorithms/searches/FibonacciSearch.java

@@ -15,20 +15,22 @@
  * Note: This algorithm requires that the input array be sorted.
  * </p>
  */
-@SuppressWarnings({"rawtypes", "unchecked"})
-public class FibonacciSearch implements SearchAlgorithm {
+public final class FibonacciSearch implements SearchAlgorithm {
 
     /**
      * Finds the index of the specified key in a sorted array using Fibonacci search.
      *
      * @param array The sorted array to search.
      * @param key The element to search for.
      * @param <T> The type of the elements in the array, which must be comparable.
-     * @throws IllegalArgumentException if the input array is not sorted or empty, or if the key is null.
+     * @throws IllegalArgumentException if the input array is null, not sorted or empty, or if the key is null.
      * @return The index of the key if found, otherwise -1.
      */
     @Override
     public <T extends Comparable<T>> int find(T[] array, T key) {
+        if (array == null) {
+            throw new IllegalArgumentException("Input array must not be null.");
+        }
         if (array.length == 0) {
             throw new IllegalArgumentException("Input array must not be empty.");
         }
@@ -76,7 +78,7 @@ public <T extends Comparable<T>> int find(T[] array, T key) {
         return -1;
     }
 
-    private boolean isSorted(Comparable[] array) {
+    private <T extends Comparable<T>> boolean isSorted(T[] array) {
         for (int i = 1; i < array.length; i++) {
             if (array[i - 1].compareTo(array[i]) > 0) {
                 return false;

src/main/java/com/thealgorithms/searches/LinearSearch.java

@@ -54,7 +54,8 @@ public class LinearSearch implements SearchAlgorithm {
      *
      * @param array List to be searched (can be unsorted)
      * @param value Key being searched for
-     * @return Location of the key, -1 if array is null or empty, or key not found
+     * @return the index of the matching element, or -1 if the array is null or empty,
+     *         the value is null, or no matching element is found; null array elements are skipped
      */
     @Override
     public <T extends Comparable<T>> int find(T[] array, T value) {

src/main/java/com/thealgorithms/searches/LowerBound.java

@@ -13,7 +13,7 @@
  * This is an extension of BinarySearch.
  *
  * <p>
- * Worst-case performance O(log n) Best-case performance O(1) Average
+ * Worst-case performance O(log n) Best-case performance O(log n) Average
  * performance O(log n) Worst-case space complexity O(1)
  *
  * @author Pratik Padalia (https://github.com/15pratik)
@@ -26,10 +26,13 @@ class LowerBound implements SearchAlgorithm {
      * @param array is an array where the LowerBound value is to be found
      * @param key is an element for which the LowerBound is to be found
      * @param <T> is any comparable type
-     * @return index of the LowerBound element
+     * @return index of the first element not less than key, or 0 if array is null/empty or key is null
      */
     @Override
     public <T extends Comparable<T>> int find(T[] array, T key) {
+        if (array == null || array.length == 0 || key == null) {
+            return 0;
+        }
         return search(array, key, 0, array.length - 1);
     }
 
@@ -51,10 +54,8 @@ private <T extends Comparable<T>> int search(T[] array, T key, int left, int rig
         int median = (left + right) >>> 1;
         int comp = key.compareTo(array[median]);
 
-        if (comp == 0) {
-            return median;
-        } else if (comp < 0) {
-            // median position can be a possible solution
+        if (comp <= 0) {
+            // key is less than or equal to array[median], median position can be a possible solution
             return search(array, key, left, median);
         } else {
             // key we are looking is greater, so we must look on the right of median position

src/main/java/com/thealgorithms/searches/SentinelLinearSearch.java

@@ -33,7 +33,7 @@
  * @see LinearSearch
  * @see SearchAlgorithm
  */
-public class SentinelLinearSearch implements SearchAlgorithm {
+public final class SentinelLinearSearch implements SearchAlgorithm {
     /**
      * Performs sentinel linear search on the given array.
      *
@@ -65,8 +65,8 @@ public <T extends Comparable<T>> int find(T[] array, T key) {
 
         int i = 0;
         // Search without bound checking since sentinel guarantees we'll find the key
-        // Null check for array element to prevent NPE when array contains null elements
-        while (array[i] != null && array[i].compareTo(key) != 0) {
+        // Null check for array element to skip nulls and prevent NPE when array contains null elements
+        while (array[i] == null || array[i].compareTo(key) != 0) {
             i++;
         }