Enhance docs, remove main, add tests in `SearchSinglyLink… (#6012)

src/main/java/com/thealgorithms/datastructures/lists/SearchSinglyLinkedListRecursion.java

@@ -1,31 +1,45 @@
 package com.thealgorithms.datastructures.lists;
 
+/**
+ * The SearchSinglyLinkedListRecursion class extends SinglyLinkedList and provides
+ * a method to search for a value in a singly linked list using recursion.
+ * <p>
+ * This class demonstrates a recursive approach to check if a given integer value is
+ * present in the linked list. The search method calls a private recursive helper method
+ * `searchRecursion`, which checks each node's value and moves to the next node if necessary.
+ * </p>
+ * <p>
+ * Example:
+ * Given a list containing the values 1 -> 2 -> 3 -> 4, calling search(3) will return `true`,
+ * while calling search(5) will return `false`.
+ * </p>
+ * <p>
+ * Complexity:
+ * <ul>
+ *   <li>Time Complexity: O(n), where n is the number of nodes in the linked list.</li>
+ *   <li>Space Complexity: O(n), due to the recursive call stack in the worst case.</li>
+ * </ul>
+ * </p>
+ */
 public class SearchSinglyLinkedListRecursion extends SinglyLinkedList {
 
-    public static void main(String[] args) {
-        SearchSinglyLinkedListRecursion list = new SearchSinglyLinkedListRecursion();
-        for (int i = 1; i <= 10; ++i) {
-            list.insert(i);
-        }
-
-        for (int i = 1; i <= 10; ++i) {
-            assert list.search(i);
-        }
-        assert !list.search(-1) && !list.search(100);
-    }
-
     /**
-     * Test if the value key is present in the list using recursion.
+     * Recursively searches for a given value in the linked list.
      *
-     * @param node the head node.
-     * @param key the value to be searched.
-     * @return {@code true} if key is present in the list, otherwise
-     * {@code false}.
+     * @param node the head node to start the search.
+     * @param key the integer value to be searched for.
+     * @return {@code true} if the value `key` is present in the list; otherwise, {@code false}.
      */
     private boolean searchRecursion(Node node, int key) {
         return (node != null && (node.value == key || searchRecursion(node.next, key)));
     }
 
+    /**
+     * Public search method to determine if a key is present in the linked list.
+     *
+     * @param key the integer value to be searched for.
+     * @return {@code true} if the value `key` is present in the list; otherwise, {@code false}.
+     */
     @Override
     public boolean search(int key) {
         return searchRecursion(getHead(), key);