Merge branch 'master' into rod_add_tests

Author: siriak

.github/workflows/build.yml

@@ -10,7 +10,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
       - name: Build with Maven
         run: mvn --batch-mode --update-snapshots verify
       - name: Upload coverage to codecov (tokenless)

.github/workflows/codeql.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v3

.github/workflows/infer.yml

@@ -18,7 +18,7 @@ jobs:
         uses: actions/setup-java@v4
         with:
           java-version: 21
-          distribution: 'adopt'
+          distribution: 'temurin'
 
       - name: Set up OCaml
         uses: ocaml/setup-ocaml@v3

DIRECTORY.md

@@ -262,6 +262,7 @@
             * [LongestValidParentheses](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/LongestValidParentheses.java)
             * [MatrixChainMultiplication](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/MatrixChainMultiplication.java)
             * [MatrixChainRecursiveTopDownMemoisation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/MatrixChainRecursiveTopDownMemoisation.java)
+            * [MaximumSumOfNonAdjacentElements](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/MaximumSumOfNonAdjacentElements.java)
             * [MinimumPathSum](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/MinimumPathSum.java)
             * [MinimumSumPartition](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/MinimumSumPartition.java)
             * [NewManShanksPrime](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/dynamicprogramming/NewManShanksPrime.java)
@@ -815,8 +816,10 @@
             * [LongestPalindromicSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LongestPalindromicSubstringTest.java)
             * [LongestValidParenthesesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/LongestValidParenthesesTest.java)
             * [MatrixChainMultiplicationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MatrixChainMultiplicationTest.java)
+            * [MaximumSumOfNonAdjacentElementsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MaximumSumOfNonAdjacentElementsTest.java)
             * [MinimumPathSumTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MinimumPathSumTest.java)
             * [MinimumSumPartitionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/MinimumSumPartitionTest.java)
+            * [NewManShanksPrimeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/NewManShanksPrimeTest.java)
             * [OptimalJobSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/OptimalJobSchedulingTest.java)
             * [PalindromicPartitioningTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/PalindromicPartitioningTest.java)
             * [PartitionProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/dynamicprogramming/PartitionProblemTest.java)

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

@@ -0,0 +1,95 @@
+package com.thealgorithms.dynamicprogramming;
+
+/**
+ * Class to find the maximum sum of non-adjacent elements in an array. This
+ * class contains two approaches: one with O(n) space complexity and another
+ * with O(1) space optimization. For more information, refer to
+ * https://takeuforward.org/data-structure/maximum-sum-of-non-adjacent-elements-dp-5/
+ */
+final class MaximumSumOfNonAdjacentElements {
+
+    private MaximumSumOfNonAdjacentElements() {
+    }
+
+    /**
+     * Approach 1: Uses a dynamic programming array to store the maximum sum at
+     * each index. Time Complexity: O(n) - where n is the length of the input
+     * array. Space Complexity: O(n) - due to the additional dp array.
+     * @param arr The input array of integers.
+     * @return The maximum sum of non-adjacent elements.
+     */
+    public static int getMaxSumApproach1(int[] arr) {
+        if (arr.length == 0) {
+            return 0; // Check for empty array
+        }
+
+        int n = arr.length;
+        int[] dp = new int[n];
+
+        // Base case: Maximum sum if only one element is present.
+        dp[0] = arr[0];
+
+        for (int ind = 1; ind < n; ind++) {
+
+            // Case 1: Do not take the current element, carry forward the previous max
+            // sum.
+            int notTake = dp[ind - 1];
+
+            // Case 2: Take the current element, add it to the max sum up to two
+            // indices before.
+            int take = arr[ind];
+            if (ind > 1) {
+                take += dp[ind - 2];
+            }
+
+            // Store the maximum of both choices in the dp array.
+            dp[ind] = Math.max(take, notTake);
+        }
+
+        return dp[n - 1];
+    }
+
+    /**
+     * Approach 2: Optimized space complexity approach using two variables instead
+     * of an array. Time Complexity: O(n) - where n is the length of the input
+     * array. Space Complexity: O(1) - as it only uses constant space for two
+     * variables.
+     * @param arr The input array of integers.
+     * @return The maximum sum of non-adjacent elements.
+     */
+    public static int getMaxSumApproach2(int[] arr) {
+        if (arr.length == 0) {
+            return 0; // Check for empty array
+        }
+
+        int n = arr.length;
+
+        // Two variables to keep track of previous two results:
+        // prev1 = max sum up to the last element (n-1)
+        // prev2 = max sum up to the element before last (n-2)
+
+        int prev1 = arr[0]; // Base case: Maximum sum for the first element.
+        int prev2 = 0;
+
+        for (int ind = 1; ind < n; ind++) {
+            // Case 1: Do not take the current element, keep the last max sum.
+            int notTake = prev1;
+
+            // Case 2: Take the current element and add it to the result from two
+            // steps back.
+            int take = arr[ind];
+            if (ind > 1) {
+                take += prev2;
+            }
+
+            // Calculate the current maximum sum and update previous values.
+            int current = Math.max(take, notTake);
+
+            // Shift prev1 and prev2 for the next iteration.
+            prev2 = prev1;
+            prev1 = current;
+        }
+
+        return prev1;
+    }
+}

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

@@ -1,25 +1,48 @@
 package com.thealgorithms.dynamicprogramming;
 
 /**
+ * The NewManShanksPrime class provides a method to determine whether the nth
+ * New Man Shanks prime matches an expected answer.
+ *
+ * <p>This is based on the New Man Shanks prime sequence defined by the recurrence
+ * relation:</p>
+ *
+ * <pre>
+ * a(n) = 2 * a(n-1) + a(n-2) for n >= 2
+ * a(0) = 1
+ * a(1) = 1
+ * </pre>
+ *
+ * <p>For more information on New Man Shanks primes, please refer to the
+ * <a href="https://en.wikipedia.org/wiki/Newman%E2%80%93Shanks%E2%80%93Williams_prime">
+ * Wikipedia article</a>.</p>
+ *
+ * <p>Note: The class is designed to be non-instantiable.</p>
+ *
  * @author <a href="https://github.com/siddhant2002">Siddhant Swarup Mallick</a>
- * Program description - To find the New Man Shanks Prime.
- * <a href="https://en.wikipedia.org/wiki/Newman%E2%80%93Shanks%E2%80%93Williams_prime">Wikipedia</a>
  */
 public final class NewManShanksPrime {
     private NewManShanksPrime() {
     }
 
+    /**
+     * Calculates the nth New Man Shanks prime and checks if it equals the
+     * expected answer.
+     *
+     * @param n the index of the New Man Shanks prime to calculate (0-based).
+     * @param expectedAnswer the expected value of the nth New Man Shanks prime.
+     * @return true if the calculated nth New Man Shanks prime matches the
+     *         expected answer; false otherwise.
+     */
     public static boolean nthManShanksPrime(int n, int expectedAnswer) {
         int[] a = new int[n + 1];
-        // array of n+1 size is initialized
         a[0] = 1;
         a[1] = 1;
-        // The 0th and 1st index position values are fixed. They are initialized as 1
+
         for (int i = 2; i <= n; i++) {
             a[i] = 2 * a[i - 1] + a[i - 2];
         }
-        // The loop is continued till n
+
         return a[n] == expectedAnswer;
-        // returns true if calculated answer matches with expected answer
     }
 }

src/test/java/com/thealgorithms/dynamicprogramming/MaximumSumOfNonAdjacentElementsTest.java

@@ -0,0 +1,52 @@
+package com.thealgorithms.dynamicprogramming;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class MaximumSumOfNonAdjacentElementsTest {
+
+    // Tests for Approach1
+    @Test
+    public void testGetMaxSumApproach1WithEmptyArray() {
+        assertEquals(0, MaximumSumOfNonAdjacentElements.getMaxSumApproach1(new int[] {})); // Empty array
+    }
+
+    @Test
+    public void testGetMaxSumApproach1WithSingleElement() {
+        assertEquals(1, MaximumSumOfNonAdjacentElements.getMaxSumApproach1(new int[] {1})); // Single element
+    }
+
+    @Test
+    public void testGetMaxSumApproach1WithTwoElementsTakeMax() {
+        assertEquals(2, MaximumSumOfNonAdjacentElements.getMaxSumApproach1(new int[] {1, 2})); // Take max of both
+    }
+
+    @Test
+    public void testGetMaxSumApproach1WithMultipleElements() {
+        assertEquals(15, MaximumSumOfNonAdjacentElements.getMaxSumApproach1(new int[] {3, 2, 5, 10, 7})); // 3 + 7 + 5
+        assertEquals(10, MaximumSumOfNonAdjacentElements.getMaxSumApproach1(new int[] {5, 1, 1, 5})); // 5 + 5
+    }
+
+    // Tests for Approach2
+    @Test
+    public void testGetMaxSumApproach2WithEmptyArray() {
+        assertEquals(0, MaximumSumOfNonAdjacentElements.getMaxSumApproach2(new int[] {})); // Empty array
+    }
+
+    @Test
+    public void testGetMaxSumApproach2WithSingleElement() {
+        assertEquals(1, MaximumSumOfNonAdjacentElements.getMaxSumApproach2(new int[] {1})); // Single element
+    }
+
+    @Test
+    public void testGetMaxSumApproach2WithTwoElementsTakeMax() {
+        assertEquals(2, MaximumSumOfNonAdjacentElements.getMaxSumApproach2(new int[] {1, 2})); // Take max of both
+    }
+
+    @Test
+    public void testGetMaxSumApproach2WithMultipleElements() {
+        assertEquals(15, MaximumSumOfNonAdjacentElements.getMaxSumApproach2(new int[] {3, 2, 5, 10, 7})); // 3 + 7 + 5
+        assertEquals(10, MaximumSumOfNonAdjacentElements.getMaxSumApproach2(new int[] {5, 1, 1, 5})); // 5 + 5
+    }
+}

src/test/java/com/thealgorithms/dynamicprogramming/NewManShanksPrimeTest.java

@@ -0,0 +1,80 @@
+package com.thealgorithms.dynamicprogramming;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for the NewManShanksPrime class.
+ * This test class verifies the correctness of the nthManShanksPrime method
+ * for various input cases.
+ */
+class NewManShanksPrimeTest {
+
+    /**
+     * Test case for the 1st New Man Shanks prime.
+     * The expected answer is 1.
+     */
+    @Test
+    void testNthManShanksPrime1() {
+        int n = 1;
+        int expectedAnswer = 1;
+        assertTrue(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 1st New Man Shanks prime should be 1.");
+    }
+
+    /**
+     * Test case for the 2nd New Man Shanks prime.
+     * The expected answer is 3.
+     */
+    @Test
+    void testNthManShanksPrime2() {
+        int n = 2;
+        int expectedAnswer = 3;
+        assertTrue(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 2nd New Man Shanks prime should be 3.");
+    }
+
+    /**
+     * Test case for the 3rd New Man Shanks prime.
+     * The expected answer is 7.
+     */
+    @Test
+    void testNthManShanksPrime3() {
+        int n = 3;
+        int expectedAnswer = 7;
+        assertTrue(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 3rd New Man Shanks prime should be 7.");
+    }
+
+    /**
+     * Test case for the 4th New Man Shanks prime.
+     * The expected answer is 17.
+     */
+    @Test
+    void testNthManShanksPrime4() {
+        int n = 4;
+        int expectedAnswer = 17;
+        assertTrue(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 4th New Man Shanks prime should be 17.");
+    }
+
+    /**
+     * Test case for the 5th New Man Shanks prime.
+     * The expected answer is 41.
+     */
+    @Test
+    void testNthManShanksPrime5() {
+        int n = 5;
+        int expectedAnswer = 41;
+        assertTrue(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 5th New Man Shanks prime should be 41.");
+    }
+
+    /**
+     * Test case with an incorrect expected answer.
+     * For n = 2, the expected answer is 3.
+     */
+    @Test
+    void testNthManShanksPrimeIncorrectAnswer() {
+        int n = 2;
+        int expectedAnswer = 4; // Incorrect expected value
+        assertFalse(NewManShanksPrime.nthManShanksPrime(n, expectedAnswer), "The 2nd New Man Shanks prime should not be 4.");
+    }
+}