Add Maximum Sum of Non-Adjacent Elements DP solution

Author: Gautamali

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

@@ -0,0 +1,26 @@
+package com.thealgorithms.dynamicprogramming;
+
+public final class MaximumSumOfNonAdjacanetElement {
+
+  private MaximumSumOfNonAdjacanetElement() {
+
+  }
+
+  public static int maxSumNonAdjacent(int[] nums) {
+    if (nums == null || nums.length == 0)
+      return 0;
+    if (nums.length == 1)
+      return nums[0];
+
+    int[] dp = new int[nums.length];
+
+    dp[0] = nums[0];
+    dp[1] = Math.max(nums[0], nums[1]);
+
+    for (int i = 2; i < nums.length; i++) {
+      dp[i] = Math.max(dp[i - 1], dp[i - 2] + nums[i]);
+    }
+
+    return dp[nums.length - 1];
+  }
+}

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

@@ -0,0 +1,48 @@
+package com.thealgorithms.dynamicprogramming;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class MaxSumNonAdjacentTest {
+  @Test
+  public void testMaxSumNonAdjacentWithMultipleElements() {
+    int[] array = { 3, 2, 5, 10, 7 };
+    assertEquals(15, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithAllPositiveNumbers() {
+    int[] array = { 5, 5, 10, 100, 10, 5 };
+    assertEquals(110, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithSingleElement() {
+    int[] array = { 7 };
+    assertEquals(7, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithEmptyArray() {
+    int[] array = {};
+    assertEquals(0, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithNegativeNumbers() {
+    int[] array = { 5, -2, 10, -4, 6 };
+    assertEquals(16, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithAllNegativeNumbers() {
+    int[] array = { -1, -2, -3, -4 };
+    assertEquals(0, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+
+  @Test
+  public void testMaxSumNonAdjacentWithLargeNumbers() {
+    int[] array = { 1000, 2000, 3000, 4000, 5000 };
+    assertEquals(9000, MaximumSumOfNonAdjacanetElement.maxSumNonAdjacent(array));
+  }
+}