Bael 1773 refactor (#4498)

* Strange git issue with README.MD, wouldn't revert the file

* BAEL-1773 Coe moved to algorithm module

core-java/src/main/java/com/baeldung/linkedlist/MiddleElementLookup.java

@@ -1,90 +0,0 @@
-package com.baeldung.linkedlist;
-
-import java.util.LinkedList;
-import java.util.Optional;
-
-import com.baeldung.linkedlist.Node;
-
-public class MiddleElementLookup {
-
-    public static Optional<String> findMiddleElementLinkedList(LinkedList<String> linkedList) {
-        if (linkedList == null || linkedList.isEmpty()) {
-            return Optional.empty();
-        }
-
-        return Optional.ofNullable(linkedList.get((linkedList.size() - 1) / 2));
-    }
-
-    public static Optional<String> findMiddleElementFromHead(Node head) {
-        if (head == null) {
-            return Optional.empty();
-        }
-
-        // calculate the size of the list
-        Node current = head;
-        int size = 1;
-        while (current.hasNext()) {
-            current = current.next();
-            size++;
-        }
-
-        // iterate till the middle element
-        current = head;
-        for (int i = 0; i < (size - 1) / 2; i++) {
-            current = current.next();
-        }
-
-        return Optional.ofNullable(current.data());
-    }
-
-    public static Optional<String> findMiddleElementFromHead1PassRecursively(Node head) {
-        if (head == null) {
-            return Optional.empty();
-        }
-
-        MiddleAuxRecursion middleAux = new MiddleAuxRecursion();
-        findMiddleRecursively(head, middleAux);
-        return Optional.ofNullable(middleAux.middle.data());
-    }
-
-    private static void findMiddleRecursively(Node node, MiddleAuxRecursion middleAux) {
-        if (node == null) {
-            // reached the end
-            middleAux.length = middleAux.length / 2;
-            return;
-        }
-        middleAux.length++;
-        findMiddleRecursively(node.next(), middleAux);
-
-        if (middleAux.length == 0) {
-            // found the middle
-            middleAux.middle = node;
-        }
-
-        middleAux.length--;
-    }
-
-    public static Optional<String> findMiddleElementFromHead1PassIteratively(Node head) {
-        if (head == null) {
-            return Optional.empty();
-        }
-
-        Node slowPointer = head;
-        Node fastPointer = head;
-
-        while (fastPointer.hasNext() && fastPointer.next()
-            .hasNext()) {
-            fastPointer = fastPointer.next()
-                .next();
-            slowPointer = slowPointer.next();
-        }
-
-        return Optional.ofNullable(slowPointer.data());
-    }
-
-    private static class MiddleAuxRecursion {
-        Node middle;
-        int length = 0;
-    }
-
-}

core-java/src/main/java/com/baeldung/linkedlist/Node.java

@@ -1,34 +0,0 @@
-package com.baeldung.linkedlist;
-
-public class Node {
-    private Node next;
-    private String data;
-
-    public Node(String data) {
-        this.data = data;
-    }
-
-    public String data() {
-        return data;
-    }
-
-    public void setData(String data) {
-        this.data = data;
-    }
-
-    public boolean hasNext() {
-        return next != null;
-    }
-
-    public Node next() {
-        return next;
-    }
-
-    public void setNext(Node next) {
-        this.next = next;
-    }
-
-    public String toString() {
-        return this.data;
-    }
-}