Merge branch 'master' into refactor/Anagrams

Author: alxkm

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

@@ -1,34 +1,44 @@
 package com.thealgorithms.others;
 
-/*
- * A left rotation operation on an array
- * shifts each of the array's elements
- * given integer n unit to the left.
+/**
+ * Provides a method to perform a left rotation on an array.
+ * A left rotation operation shifts each element of the array
+ * by a specified number of positions to the left.
  *
  * @author sangin-lee
  */
-
 public final class ArrayLeftRotation {
     private ArrayLeftRotation() {
     }
 
-    /*
-     * Returns the result of left rotation of given array arr and integer n
-     *
-     * @param arr : int[] given array
-     *
-     * @param n : int given integer
+    /**
+     * Performs a left rotation on the given array by the specified number of positions.
      *
-     * @return : int[] result of left rotation
+     * @param arr the array to be rotated
+     * @param n the number of positions to rotate the array to the left
+     * @return a new array containing the elements of the input array rotated to the left
      */
     public static int[] rotateLeft(int[] arr, int n) {
         int size = arr.length;
-        int[] dst = new int[size];
+
+        // Handle cases where array is empty or rotation count is zero
+        if (size == 0 || n <= 0) {
+            return arr.clone();
+        }
+
+        // Normalize the number of rotations
         n = n % size;
+        if (n == 0) {
+            return arr.clone();
+        }
+
+        int[] rotated = new int[size];
+
+        // Perform rotation
         for (int i = 0; i < size; i++) {
-            dst[i] = arr[n];
-            n = (n + 1) % size;
+            rotated[i] = arr[(i + n) % size];
         }
-        return dst;
+
+        return rotated;
     }
 }

src/main/java/com/thealgorithms/stacks/BalancedBrackets.java

@@ -59,26 +59,22 @@ public static boolean isBalanced(String brackets) {
             switch (bracket) {
             case '(':
             case '[':
+            case '<':
             case '{':
                 bracketsStack.push(bracket);
                 break;
             case ')':
             case ']':
+            case '>':
             case '}':
                 if (bracketsStack.isEmpty() || !isPaired(bracketsStack.pop(), bracket)) {
                     return false;
                 }
                 break;
             default:
-                /* other character is invalid */
                 return false;
             }
         }
         return bracketsStack.isEmpty();
     }
-
-    public static void main(String[] args) {
-        assert isBalanced("[()]{}{[()()]()}");
-        assert !isBalanced("[(])");
-    }
 }

src/main/java/com/thealgorithms/stacks/DecimalToAnyUsingStack.java

@@ -6,50 +6,33 @@ public final class DecimalToAnyUsingStack {
     private DecimalToAnyUsingStack() {
     }
 
-    public static void main(String[] args) {
-        assert convert(0, 2).equals("0");
-        assert convert(30, 2).equals("11110");
-        assert convert(30, 8).equals("36");
-        assert convert(30, 10).equals("30");
-        assert convert(30, 16).equals("1E");
-    }
-
     /**
-     * Convert decimal number to another radix
+     * Convert a decimal number to another radix.
      *
      * @param number the number to be converted
      * @param radix the radix
-     * @return another radix
-     * @throws ArithmeticException if <tt>number</tt> or <tt>radius</tt> is
-     * invalid
+     * @return the number represented in the new radix as a String
+     * @throws IllegalArgumentException if <tt>number</tt> is negative or <tt>radix</tt> is not between 2 and 16 inclusive
      */
-    private static String convert(int number, int radix) {
+    public static String convert(int number, int radix) {
+        if (number < 0) {
+            throw new IllegalArgumentException("Number must be non-negative.");
+        }
         if (radix < 2 || radix > 16) {
-            throw new ArithmeticException(String.format("Invalid input -> number:%d,radius:%d", number, radix));
+            throw new IllegalArgumentException(String.format("Invalid radix: %d. Radix must be between 2 and 16.", radix));
+        }
+
+        if (number == 0) {
+            return "0";
         }
-        char[] tables = {
-            '0',
-            '1',
-            '2',
-            '3',
-            '4',
-            '5',
-            '6',
-            '7',
-            '8',
-            '9',
-            'A',
-            'B',
-            'C',
-            'D',
-            'E',
-            'F',
-        };
+
+        char[] tables = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+
         Stack<Character> bits = new Stack<>();
-        do {
+        while (number > 0) {
             bits.push(tables[number % radix]);
             number = number / radix;
-        } while (number != 0);
+        }
 
         StringBuilder result = new StringBuilder();
         while (!bits.isEmpty()) {

src/main/java/com/thealgorithms/strings/CheckVowels.java

@@ -1,7 +1,5 @@
 package com.thealgorithms.strings;
 
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -10,24 +8,24 @@
  * alphabet. Wikipedia: https://en.wikipedia.org/wiki/Alphabetical_order
  */
 public final class CheckVowels {
+    private static final Set<Character> VOWELS = Set.of('a', 'e', 'i', 'o', 'u');
+
     private CheckVowels() {
     }
 
-    private static final Set<Character> VOWELS = new HashSet<>(Arrays.asList('a', 'e', 'i', 'o', 'u'));
-
     /**
-     * Check if a string is has vowels or not
+     * Checks if a string contains any vowels.
      *
-     * @param input a string
-     * @return {@code true} if given string has vowels, otherwise {@code false}
+     * @param input a string to check
+     * @return {@code true} if the given string contains at least one vowel, otherwise {@code false}
      */
     public static boolean hasVowels(String input) {
-        if (input == null) {
+        if (input == null || input.isEmpty()) {
             return false;
         }
-        input = input.toLowerCase();
-        for (int i = 0; i < input.length(); i++) {
-            if (VOWELS.contains(input.charAt(i))) {
+
+        for (char c : input.toLowerCase().toCharArray()) {
+            if (VOWELS.contains(c)) {
                 return true;
             }
         }

src/test/java/com/thealgorithms/others/ArrayLeftRotationTest.java

@@ -44,4 +44,11 @@ void testForHigherSizeStep() {
         int[] result = ArrayLeftRotation.rotateLeft(arr, n);
         assertArrayEquals(expected, result);
     }
+
+    @Test
+    void testForEmptyArray() {
+        int[] arr = {};
+        int[] result = ArrayLeftRotation.rotateLeft(arr, 3);
+        assertArrayEquals(arr, result);
+    }
 }

src/test/java/com/thealgorithms/stacks/BalancedBracketsTest.java

@@ -0,0 +1,36 @@
+package com.thealgorithms.stacks;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class BalancedBracketsTest {
+
+    @ParameterizedTest
+    @CsvSource({"(, )", "[, ]", "{, }", "<, >"})
+    void testIsPairedTrue(char opening, char closing) {
+        assertTrue(BalancedBrackets.isPaired(opening, closing));
+    }
+
+    @ParameterizedTest
+    @CsvSource({"(, ]", "[, )", "{, >", "<, )", "a, b", "!, @"})
+    void testIsPairedFalse(char opening, char closing) {
+        assertFalse(BalancedBrackets.isPaired(opening, closing));
+    }
+
+    @ParameterizedTest
+    @CsvSource({"'[()]{}{[()()]()}', true", "'()', true", "'[]', true", "'{}', true", "'<>', true", "'[{<>}]', true", "'', true", "'[(])', false", "'([)]', false", "'{[<]>}', false", "'[', false", "')', false", "'[{', false", "']', false", "'[a+b]', false", "'a+b', false"})
+    void testIsBalanced(String input, boolean expected) {
+        assertEquals(expected, BalancedBrackets.isBalanced(input));
+    }
+
+    @Test
+    void testIsBalancedNull() {
+        assertThrows(IllegalArgumentException.class, () -> BalancedBrackets.isBalanced(null));
+    }
+}

src/test/java/com/thealgorithms/stacks/DecimalToAnyUsingStackTest.java

@@ -0,0 +1,45 @@
+package com.thealgorithms.stacks;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class DecimalToAnyUsingStackTest {
+
+    @Test
+    void testConvertToBinary() {
+        assertEquals("0", DecimalToAnyUsingStack.convert(0, 2));
+        assertEquals("11110", DecimalToAnyUsingStack.convert(30, 2));
+    }
+
+    @Test
+    void testConvertToOctal() {
+        assertEquals("36", DecimalToAnyUsingStack.convert(30, 8));
+    }
+
+    @Test
+    void testConvertToDecimal() {
+        assertEquals("30", DecimalToAnyUsingStack.convert(30, 10));
+    }
+
+    @Test
+    void testConvertToHexadecimal() {
+        assertEquals("1E", DecimalToAnyUsingStack.convert(30, 16));
+    }
+
+    @Test
+    void testInvalidRadix() {
+        IllegalArgumentException thrown = assertThrows(IllegalArgumentException.class, () -> DecimalToAnyUsingStack.convert(30, 1));
+        assertEquals("Invalid radix: 1. Radix must be between 2 and 16.", thrown.getMessage());
+
+        thrown = assertThrows(IllegalArgumentException.class, () -> DecimalToAnyUsingStack.convert(30, 17));
+        assertEquals("Invalid radix: 17. Radix must be between 2 and 16.", thrown.getMessage());
+    }
+
+    @Test
+    void testNegativeNumber() {
+        IllegalArgumentException thrown = assertThrows(IllegalArgumentException.class, () -> DecimalToAnyUsingStack.convert(-30, 2));
+        assertEquals("Number must be non-negative.", thrown.getMessage());
+    }
+}

src/test/java/com/thealgorithms/strings/CheckVowelsTest.java

@@ -1,17 +1,15 @@
 package com.thealgorithms.strings;
 
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
 
-public class CheckVowelsTest {
+class CheckVowelsTest {
 
-    @Test
-    public void isVowel() {
-        assertTrue(CheckVowels.hasVowels("foo"));
-        assertTrue(CheckVowels.hasVowels("bar"));
-        assertFalse(CheckVowels.hasVowels("why"));
-        assertFalse(CheckVowels.hasVowels("myths"));
+    @ParameterizedTest
+    @CsvSource({"'foo', true", "'bar', true", "'why', false", "'myths', false", "'', false", "'AEIOU', true", "'bcdfghjklmnpqrstvwxyz', false", "'AeIoU', true"})
+    void testHasVowels(String input, boolean expected) {
+        assertEquals(CheckVowels.hasVowels(input), expected);
     }
 }