Merge branch 'master' into master

Author: paren-thesis

pmd-exclude.properties

@@ -55,7 +55,6 @@ com.thealgorithms.maths.SumOfArithmeticSeries=UselessParentheses
 com.thealgorithms.maths.TrinomialTriangle=UselessParentheses
 com.thealgorithms.maths.VampireNumber=CollapsibleIfStatements
 com.thealgorithms.maths.Volume=UselessParentheses
-com.thealgorithms.matrixexponentiation.Fibonacci=UnnecessaryFullyQualifiedName
 com.thealgorithms.misc.Sparsity=UselessParentheses
 com.thealgorithms.misc.ThreeSumProblem=UselessParentheses
 com.thealgorithms.misc.WordBoggle=UselessParentheses

pom.xml

@@ -12,7 +12,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
-        <assertj.version>3.27.0</assertj.version>
+        <assertj.version>3.27.2</assertj.version>
     </properties>
 
     <dependencyManagement>
@@ -43,7 +43,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>5.14.2</version>
+            <version>5.15.2</version>
             <scope>test</scope>
         </dependency>
 
@@ -125,7 +125,7 @@
                     <dependency>
                     <groupId>com.puppycrawl.tools</groupId>
                     <artifactId>checkstyle</artifactId>
-                    <version>10.21.0</version>
+                    <version>10.21.1</version>
                     </dependency>
                 </dependencies>
             </plugin>

spotbugs-exclude.xml

@@ -41,9 +41,6 @@
     <Match>
         <Bug pattern="INT_BAD_REM_BY_1" />
     </Match>
-    <Match>
-        <Bug pattern="ICAST_IDIV_CAST_TO_DOUBLE" />
-    </Match>
     <Match>
         <Bug pattern="FE_FLOATING_POINT_EQUALITY" />
     </Match>

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

@@ -37,14 +37,14 @@ public static double average(double[] numbers) {
      * @return the average of the given numbers
      * @throws IllegalArgumentException if the input array is {@code null} or empty
      */
-    public static double average(int[] numbers) {
+    public static long average(int[] numbers) {
         if (numbers == null || numbers.length == 0) {
             throw new IllegalArgumentException("Numbers array cannot be empty or null");
         }
         long sum = 0;
         for (int number : numbers) {
             sum += number;
         }
-        return (double) (sum / numbers.length);
+        return sum / numbers.length;
     }
 }

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

@@ -1,78 +1,48 @@
 package com.thealgorithms.maths;
 
 import java.util.ArrayList;
-import java.util.Collections;
 
 /**
- * n number theory, a vampire number (or true vampire number) is a composite
+ * In number theory, a vampire number (or true vampire number) is a composite
  * natural number with an even number of digits, that can be factored into two
  * natural numbers each with half as many digits as the original number and not
  * both with trailing zeroes, where the two factors contain precisely all the
  * digits of the original number, in any order, counting multiplicity. The first
- * vampire number is 1260 = 21 × 60. *
+ * vampire number is 1260 = 21 × 60.
  *
- * <p>
- * link: https://en.wikipedia.org/wiki/Vampire_number *
- *
- * <p>
+ * @see <a href='https://en.wikipedia.org/wiki/Vampire_number'>Vampire number on Wikipedia</a>
  */
 public final class VampireNumber {
+    // Forbid instantiation.
     private VampireNumber() {
     }
 
-    public static void main(String[] args) {
-        test(10, 1000);
-    }
-
-    static void test(int startValue, int stopValue) {
-        int countofRes = 1;
-        StringBuilder res = new StringBuilder();
-
-        for (int i = startValue; i <= stopValue; i++) {
-            for (int j = i; j <= stopValue; j++) {
-                // System.out.println(i+ " "+ j);
-                if (isVampireNumber(i, j, true)) {
-                    countofRes++;
-                    res.append("").append(countofRes).append(": = ( ").append(i).append(",").append(j).append(" = ").append(i * j).append(")").append("\n");
-                }
-            }
-        }
-        System.out.println(res);
-    }
-
-    static boolean isVampireNumber(int a, int b, boolean noPseudoVamireNumbers) {
-        // this is for pseudoVampireNumbers  pseudovampire number need not be of length n/2 digits
-        // for example 126 = 6 x 21
-        if (noPseudoVamireNumbers) {
-            if (a * 10 <= b || b * 10 <= a) {
-                return false;
-            }
+    static boolean isVampireNumber(int a, int b, boolean ignorePseudoVampireNumbers) {
+        // Pseudo vampire numbers don't have to be of n/2 digits. E.g., 126 = 6 x 21 is such a number.
+        if (ignorePseudoVampireNumbers && String.valueOf(a).length() != String.valueOf(b).length()) {
+            return false;
         }
 
-        String mulDigits = splitIntoDigits(a * b, 0);
-        String faktorDigits = splitIntoDigits(a, b);
+        String mulDigits = splitIntoSortedDigits(a * b);
+        String factorDigits = splitIntoSortedDigits(a, b);
 
-        return mulDigits.equals(faktorDigits);
+        return mulDigits.equals(factorDigits);
     }
 
-    // methode to Split the numbers to Digits
-    static String splitIntoDigits(int num, int num2) {
-        StringBuilder res = new StringBuilder();
-
+    // Method to split a pair of numbers to digits and sort them in the ascending order.
+    static String splitIntoSortedDigits(int... nums) {
+        // Collect all digits in a list.
         ArrayList<Integer> digits = new ArrayList<>();
-        while (num > 0) {
-            digits.add(num % 10);
-            num /= 10;
-        }
-        while (num2 > 0) {
-            digits.add(num2 % 10);
-            num2 /= 10;
-        }
-        Collections.sort(digits);
-        for (int i : digits) {
-            res.append(i);
+        for (int num : nums) {
+            while (num > 0) {
+                digits.add(num % 10);
+                num /= 10;
+            }
         }
 
+        // Sort all digits and convert to String.
+        StringBuilder res = new StringBuilder();
+        digits.stream().sorted().forEach(res::append);
         return res.toString();
     }
 }

src/main/java/com/thealgorithms/misc/InverseOfMatrix.java renamed to src/main/java/com/thealgorithms/matrix/InverseOfMatrix.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.misc;
+package com.thealgorithms.matrix;
 
 /**
  * This class provides methods to compute the inverse of a square matrix

src/main/java/com/thealgorithms/misc/MatrixTranspose.java renamed to src/main/java/com/thealgorithms/matrix/MatrixTranspose.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.misc;
+package com.thealgorithms.matrix;
 
 /**
  *

src/main/java/com/thealgorithms/misc/MedianOfMatrix.java renamed to src/main/java/com/thealgorithms/matrix/MedianOfMatrix.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.misc;
+package com.thealgorithms.matrix;
 
 import java.util.ArrayList;
 import java.util.Collections;

src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java renamed to src/main/java/com/thealgorithms/matrix/MirrorOfMatrix.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.misc;
+package com.thealgorithms.matrix;
 
 // Problem Statement
 /*

src/main/java/com/thealgorithms/others/PrintAMatrixInSpiralOrder.java renamed to src/main/java/com/thealgorithms/matrix/PrintAMatrixInSpiralOrder.java

@@ -1,62 +1,62 @@
-package com.thealgorithms.others;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class PrintAMatrixInSpiralOrder {
-    /**
-     * Search a key in row and column wise sorted matrix
-     *
-     * @param matrix matrix to be searched
-     * @param row    number of rows matrix has
-     * @param col    number of columns matrix has
-     * @author Sadiul Hakim : https://github.com/sadiul-hakim
-     */
-
-    public List<Integer> print(int[][] matrix, int row, int col) {
-
-        // r traverses matrix row wise from first
-        int r = 0;
-        // c traverses matrix column wise from first
-        int c = 0;
-        int i;
-
-        List<Integer> result = new ArrayList<>();
-
-        while (r < row && c < col) {
-            // print first row of matrix
-            for (i = c; i < col; i++) {
-                result.add(matrix[r][i]);
-            }
-
-            // increase r by one because first row printed
-            r++;
-
-            // print last column
-            for (i = r; i < row; i++) {
-                result.add(matrix[i][col - 1]);
-            }
-
-            // decrease col by one because last column has been printed
-            col--;
-
-            // print rows from last except printed elements
-            if (r < row) {
-                for (i = col - 1; i >= c; i--) {
-                    result.add(matrix[row - 1][i]);
-                }
-
-                row--;
-            }
-
-            // print columns from first except printed elements
-            if (c < col) {
-                for (i = row - 1; i >= r; i--) {
-                    result.add(matrix[i][c]);
-                }
-                c++;
-            }
-        }
-        return result;
-    }
-}
+package com.thealgorithms.matrix;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PrintAMatrixInSpiralOrder {
+    /**
+     * Search a key in row and column wise sorted matrix
+     *
+     * @param matrix matrix to be searched
+     * @param row    number of rows matrix has
+     * @param col    number of columns matrix has
+     * @author Sadiul Hakim : https://github.com/sadiul-hakim
+     */
+
+    public List<Integer> print(int[][] matrix, int row, int col) {
+
+        // r traverses matrix row wise from first
+        int r = 0;
+        // c traverses matrix column wise from first
+        int c = 0;
+        int i;
+
+        List<Integer> result = new ArrayList<>();
+
+        while (r < row && c < col) {
+            // print first row of matrix
+            for (i = c; i < col; i++) {
+                result.add(matrix[r][i]);
+            }
+
+            // increase r by one because first row printed
+            r++;
+
+            // print last column
+            for (i = r; i < row; i++) {
+                result.add(matrix[i][col - 1]);
+            }
+
+            // decrease col by one because last column has been printed
+            col--;
+
+            // print rows from last except printed elements
+            if (r < row) {
+                for (i = col - 1; i >= c; i--) {
+                    result.add(matrix[row - 1][i]);
+                }
+
+                row--;
+            }
+
+            // print columns from first except printed elements
+            if (c < col) {
+                for (i = row - 1; i >= r; i--) {
+                    result.add(matrix[i][c]);
+                }
+                c++;
+            }
+        }
+        return result;
+    }
+}

src/main/java/com/thealgorithms/others/RotateMatrixBy90Degrees.java renamed to src/main/java/com/thealgorithms/matrix/RotateMatrixBy90Degrees.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.others;
+package com.thealgorithms.matrix;
 
 import java.util.Scanner;
 /**

src/main/java/com/thealgorithms/matrixexponentiation/Fibonacci.java renamed to src/main/java/com/thealgorithms/matrix/matrixexponentiation/Fibonacci.java

@@ -1,4 +1,4 @@
-package com.thealgorithms.matrixexponentiation;
+package com.thealgorithms.matrix.matrixexponentiation;
 
 import java.util.Scanner;
 
@@ -55,14 +55,14 @@ private static int[][] matrixMultiplication(int[][] matrix1, int[][] matrix2) {
      */
     public static int[][] fib(int n) {
         if (n == 0) {
-            return Fibonacci.IDENTITY_MATRIX;
+            return IDENTITY_MATRIX;
         } else {
             int[][] cachedResult = fib(n / 2);
             int[][] matrixExpResult = matrixMultiplication(cachedResult, cachedResult);
             if (n % 2 == 0) {
                 return matrixExpResult;
             } else {
-                return matrixMultiplication(Fibonacci.FIB_MATRIX, matrixExpResult);
+                return matrixMultiplication(FIB_MATRIX, matrixExpResult);
             }
         }
     }

src/main/java/com/thealgorithms/others/KochSnowflake.java

@@ -105,7 +105,7 @@ public static BufferedImage getKochSnowflake(int imageWidth, int steps) {
         double offsetX = imageWidth / 10.;
         double offsetY = imageWidth / 3.7;
         Vector2 vector1 = new Vector2(offsetX, offsetY);
-        Vector2 vector2 = new Vector2(imageWidth / 2, Math.sin(Math.PI / 3) * imageWidth * 0.8 + offsetY);
+        Vector2 vector2 = new Vector2(imageWidth / 2.0, Math.sin(Math.PI / 3.0) * imageWidth * 0.8 + offsetY);
         Vector2 vector3 = new Vector2(imageWidth - offsetX, offsetY);
         ArrayList<Vector2> initialVectors = new ArrayList<Vector2>();
         initialVectors.add(vector1);