style: enabled InnerAssignment in checkstyle (#5162)

* style: enabled InnerAssignment in checkstyle

* Refactor code formatting in KnapsackMemoization.java and UnionFind.java

* style: remove redundant blank line

* style: mark `includeCurrentItem` and `excludeCurrentItem` as `final`

* style: remove `KnapsackMemoization` from `pmd-exclude.properties`

* style: use `final`

---------

Co-authored-by: Piotr Idzik <[email protected]>

Author: CodaBlurd

checkstyle.xml

@@ -164,7 +164,7 @@
     <module name="EqualsHashCode"/>
     <!-- TODO <module name="HiddenField"/> -->
     <module name="IllegalInstantiation"/>
-    <!-- TODO <module name="InnerAssignment"/> -->
+    <module name="InnerAssignment"/>
     <!-- TODO <module name="MagicNumber"/> -->
     <!-- TODO <module name="MissingSwitchDefault"/> -->
     <!-- TODO <module name="MultipleVariableDeclarations"/> -->

pmd-exclude.properties

@@ -33,7 +33,6 @@ com.thealgorithms.devutils.nodes.SimpleTreeNode=UselessParentheses
 com.thealgorithms.devutils.nodes.TreeNode=UselessParentheses
 com.thealgorithms.divideandconquer.ClosestPair=UnnecessaryFullyQualifiedName,UselessParentheses
 com.thealgorithms.divideandconquer.Point=UselessParentheses
-com.thealgorithms.dynamicprogramming.KnapsackMemoization=UselessParentheses
 com.thealgorithms.dynamicprogramming.MatrixChainMultiplication=UselessParentheses
 com.thealgorithms.dynamicprogramming.ShortestSuperSequence=UselessParentheses
 com.thealgorithms.dynamicprogramming.UniquePaths=UnnecessarySemicolon

src/main/java/com/thealgorithms/ciphers/ProductCipher.java

@@ -26,8 +26,8 @@ public static void main(String[] args) {
 
             // Transposition encryption
             String transpositionInput = substitutionOutput.toString();
-            int modulus;
-            if ((modulus = transpositionInput.length() % n) != 0) {
+            int modulus = transpositionInput.length() % n;
+            if (modulus != 0) {
                 modulus = n - modulus;
 
                 for (; modulus != 0; modulus--) {

src/main/java/com/thealgorithms/datastructures/dynamicarray/DynamicArray.java

@@ -121,7 +121,8 @@ private void fastRemove(final Object[] elements, final int index) {
             System.arraycopy(elements, index + 1, elements, index, newSize - index);
         }
 
-        elements[this.size = newSize] = null;
+        this.size = newSize;
+        this.elements[this.size] = null;
     }
 
     private E getElement(final int index) {

src/main/java/com/thealgorithms/datastructures/heaps/LeftistHeap.java

@@ -20,7 +20,8 @@ private final class Node {
         // Node constructor setting the data element and left/right pointers to null
         private Node(int element) {
             this.element = element;
-            left = right = null;
+            left = null;
+            right = null;
             npl = 0;
         }
     }

src/main/java/com/thealgorithms/datastructures/queues/CircularQueue.java

@@ -54,7 +54,8 @@ public int deQueue() {
             int res = arr[beginningOfQueue];
             arr[beginningOfQueue] = Integer.MIN_VALUE;
             if (beginningOfQueue == topOfQueue) {
-                beginningOfQueue = topOfQueue = -1;
+                beginningOfQueue = -1;
+                topOfQueue = -1;
             } else if (beginningOfQueue + 1 == size) {
                 beginningOfQueue = 0;
             } else {

src/main/java/com/thealgorithms/datastructures/queues/LinkedQueue.java

@@ -44,7 +44,9 @@ static class Node<T> {
      * Init LinkedQueue
      */
     public LinkedQueue() {
-        front = rear = new Node<>();
+
+        front = new Node<>();
+        rear = front;
     }
 
     /**
@@ -146,7 +148,8 @@ public boolean hasNext() {
 
             @Override
             public T next() {
-                return (node = node.next).data;
+                node = node.next;
+                return node.data;
             }
         };
     }

src/main/java/com/thealgorithms/datastructures/trees/PrintTopViewofTree.java

@@ -15,7 +15,8 @@ class TreeNode {
     // Constructor
     TreeNode(int key) {
         this.key = key;
-        left = right = null;
+        left = null;
+        right = null;
     }
 }
 

src/main/java/com/thealgorithms/datastructures/trees/RedBlackBST.java

@@ -201,7 +201,8 @@ Node treeMinimum(Node subTreeRoot) {
     }
 
     boolean delete(Node z) {
-        if ((z = findNode(z, root)) == null) {
+        Node result = findNode(z, root);
+        if (result == null) {
             return false;
         }
         Node x;

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

@@ -40,8 +40,15 @@ int solveKnapsackRecursive(int capacity, int[] weights, int[] profits, int numOf
             dpTable[numOfItems][capacity] = solveKnapsackRecursive(capacity, weights, profits, numOfItems - 1, dpTable);
             return dpTable[numOfItems][capacity];
         } else {
-            // Return value of table after storing
-            return dpTable[numOfItems][capacity] = Math.max((profits[numOfItems - 1] + solveKnapsackRecursive(capacity - weights[numOfItems - 1], weights, profits, numOfItems - 1, dpTable)), solveKnapsackRecursive(capacity, weights, profits, numOfItems - 1, dpTable));
+            // case 1. include the item, if it is less than the capacity
+            final int includeCurrentItem = profits[numOfItems - 1] + solveKnapsackRecursive(capacity - weights[numOfItems - 1], weights, profits, numOfItems - 1, dpTable);
+
+            // case 2. exclude the item if it is more than the capacity
+            final int excludeCurrentItem = solveKnapsackRecursive(capacity, weights, profits, numOfItems - 1, dpTable);
+
+            // Store the value of function call stack in table and return
+            dpTable[numOfItems][capacity] = Math.max(includeCurrentItem, excludeCurrentItem);
+            return dpTable[numOfItems][capacity];
         }
     }
 }