Merge branch 'master' into fix/maze-recursion-boundary-validation

Author: NithinU2802

.github/workflows/codeql.yml

@@ -30,15 +30,15 @@ jobs:
           distribution: 'temurin'
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.39.0
+        uses: github/codeql-action/init@v4.39.1
         with:
           languages: 'java-kotlin'
 
       - name: Build
         run: mvn --batch-mode --update-snapshots verify
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.39.0
+        uses: github/codeql-action/analyze@v4.39.1
         with:
           category: "/language:java-kotlin"
 
@@ -55,12 +55,12 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.39.0
+        uses: github/codeql-action/init@v4.39.1
         with:
           languages: 'actions'
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.39.0
+        uses: github/codeql-action/analyze@v4.39.1
         with:
           category: "/language:actions"
 ...

.github/workflows/project_structure.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-python@v7.0.0
+      - uses: actions/setup-python@v7.1.0
         with:
           python-version: '3.13'
 

pom.xml

@@ -61,7 +61,7 @@
         <plugins>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>3.6.0</version>
+                <version>3.6.1</version>
                 <configuration>
                     <forkNode implementation="org.apache.maven.plugin.surefire.extensions.SurefireForkNodeFactory"/>
                 </configuration>
@@ -82,7 +82,7 @@
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
-                <version>0.8.15</version>
+                <version>0.8.16</version>
                 <executions>
                     <execution>
                         <goals>

src/main/java/com/thealgorithms/datastructures/lists/SkipList.java

@@ -121,6 +121,9 @@ public void remove(E e) {
                 current = next;
             }
         }
+        if (layer < 0) {
+            return; // not found, nothing to unlink
+        }
         for (int i = 0; i <= layer; i++) {
             current.previous(i).setNext(i, current.next(i));
             if (current.next(i) != null) {

src/main/java/com/thealgorithms/dynamicprogramming/CatalanNumber.java

@@ -21,8 +21,16 @@ private CatalanNumber() {
      * n > 50, BigInteger class should be used instead long
      *
      * @return catalanArray[n] the nth Catalan number
+     * @throws IllegalArgumentException if n is negative
      */
     static long findNthCatalan(int n) {
+        if (n < 0) {
+            throw new IllegalArgumentException("n must be non-negative");
+        }
+        if (n <= 1) {
+            return 1;
+        }
+
         // Array to store the results of subproblems i.e Catalan numbers from [1...n-1]
         long[] catalanArray = new long[n + 1];
 

src/main/java/com/thealgorithms/maths/BinomialCoefficient.java

@@ -21,9 +21,14 @@ private BinomialCoefficient() {
      * @param numberOfObjects Number of objects to be chosen from total_objects
      * @return number of ways in which no_of_objects objects can be chosen from total_objects
      *     objects
+     * @throws IllegalArgumentException if totalObjects or numberOfObjects is negative
      */
 
     public static int binomialCoefficient(int totalObjects, int numberOfObjects) {
+        if (totalObjects < 0 || numberOfObjects < 0) {
+            throw new IllegalArgumentException("Arguments must be non-negative.");
+        }
+
         // Base Case
         if (numberOfObjects > totalObjects) {
             return 0;

src/main/java/com/thealgorithms/searches/BinarySearch2dArray.java

@@ -28,13 +28,13 @@ private BinarySearch2dArray() {
      * @return An array containing the row and column indices of the target, or [-1,
      *         -1] if the target is not found.
      */
-    static int[] binarySearch(int[][] arr, int target) {
+    public static int[] binarySearch(int[][] arr, int target) {
         int rowCount = arr.length;
         int colCount = arr[0].length;
 
         // Edge case: If there's only one row, search that row directly.
         if (rowCount == 1) {
-            return binarySearch(arr, target, 0, 0, colCount);
+            return binarySearch(arr, target, 0, 0, colCount - 1);
         }
 
         // Set initial boundaries for binary search on rows.
@@ -70,6 +70,11 @@ else if (arr[midRow][midCol] < target) {
             return new int[] {endRow, midCol};
         }
 
+        // Edge case: If there is only one column, target cannot be outside midCol.
+        if (colCount == 1) {
+            return new int[] {-1, -1};
+        }
+
         // If target is smaller than the element in the left of startRow, perform a
         // binary search on the left of startRow.
         if (target <= arr[startRow][midCol - 1]) {

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

@@ -1,27 +1,25 @@
 package com.thealgorithms.searches;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * Boyer-Moore string search algorithm.
  * Efficient algorithm for substring search.
  * https://en.wikipedia.org/wiki/Boyer%E2%80%93Moore_string-search_algorithm
  */
 public class BoyerMoore {
 
-    private final int radix; // Radix (number of possible characters)
-    private final int[] right; // Bad character rule table
+    private final Map<Character, Integer> right; // Bad character rule table: last index of each pattern character
     private final String pattern;
 
     public BoyerMoore(String pat) {
         this.pattern = pat;
-        this.radix = 256;
-        this.right = new int[radix];
-
-        for (int c = 0; c < radix; c++) {
-            right[c] = -1;
-        }
+        // A map instead of a 256-entry array, so characters outside extended ASCII work too
+        this.right = new HashMap<>();
 
         for (int j = 0; j < pat.length(); j++) {
-            right[pat.charAt(j)] = j;
+            right.put(pat.charAt(j), j);
         }
     }
 
@@ -40,7 +38,7 @@ public int search(String text) {
                 char txtChar = text.charAt(i + j);
                 char patChar = pattern.charAt(j);
                 if (patChar != txtChar) {
-                    skip = Math.max(1, j - right[txtChar]);
+                    skip = Math.max(1, j - right.getOrDefault(txtChar, -1));
                     break;
                 }
             }

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

@@ -13,9 +13,14 @@ public static int search(String pattern, String text, int primeNumber) {
         int index = -1; // -1 here represents not found
         int patternLength = pattern.length();
         int textLength = text.length();
-        int hashForPattern = 0;
-        int hashForText = 0;
-        int h = 1;
+        if (patternLength > textLength) {
+            return index;
+        }
+
+        // long, so hash * ALPHABET_SIZE cannot overflow for large primes such as 1_000_000_007
+        long hashForPattern = 0;
+        long hashForText = 0;
+        long h = 1;
 
         // The value of h would be "pow(d, patternLength-1)%primeNumber"
         for (int i = 0; i < patternLength - 1; i++) {

src/test/java/com/thealgorithms/datastructures/lists/SkipListTest.java

@@ -106,6 +106,20 @@ void testClearViaRemovals() {
         assertEquals(0, skipList.size());
     }
 
+    @Test
+    @DisplayName("Removing a missing element leaves the list unchanged")
+    void testRemoveMissing() {
+        skipList.remove("missing");
+        assertEquals(0, skipList.size());
+
+        skipList.add("a");
+        skipList.add("c");
+        skipList.remove("b");
+        assertEquals(2, skipList.size());
+        assertEquals("a", skipList.get(0));
+        assertEquals("c", skipList.get(1));
+    }
+
     private SkipList<String> createSkipList() {
         SkipList<String> s = new SkipList<>();
         String[] values = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k"};