Corrected comments in playground. Fixed a logic bug when inserting/appending a node

Author: m-alani

Linked List/LinkedList.playground/Contents.swift

@@ -282,7 +282,7 @@ linkedList.count               // 4
 linkedList[0]                  // 1
 
 // Infer the type from the array
-let listArrayLiteral2: LinkedList? = ["Swift", "Algorithm", "Club"]
-listArrayLiteral2?.count        // 3
-listArrayLiteral2?[0]           // "Swift"
-listArrayLiteral2?.removeLast()  // "Club"
+let listArrayLiteral2: LinkedList = ["Swift", "Algorithm", "Club"]
+listArrayLiteral2.count        // 3
+listArrayLiteral2[0]           // "Swift"
+listArrayLiteral2.removeLast()  // "Club"

Linked List/LinkedList.swift

@@ -71,7 +71,8 @@ public final class LinkedList<T> {
         self.append(newNode)
     }
 
-    public func append(_ newNode: Node) {
+    public func append(_ node: Node) {
+        let newNode = Node(value: node.value)
         if let lastNode = last {
             newNode.previous = lastNode
             lastNode.next = newNode
@@ -102,9 +103,9 @@ public final class LinkedList<T> {
         self.insert(newNode, atIndex: index)
     }
 
-    public func insert(_ newNode: Node, atIndex index: Int) {
+    public func insert(_ node: Node, atIndex index: Int) {
         let (prev, next) = nodesBeforeAndAfter(index: index)
-        
+        let newNode = Node(value: node.value)
         newNode.previous = prev
         newNode.next = next
         prev?.next = newNode