Improve LinkedList Array initliasier

Linked List/LinkedList.swift

@@ -270,8 +270,18 @@ extension LinkedList {
 extension LinkedList {
     convenience init(array: Array<T>) {
         self.init()
-
-        array.forEach { append($0) }
+        guard let first = array.first else {
+            return
+        }
+        var node = Node(value: first)
+        append(node)
+
+        for item in array[1...] {
+            let next = Node(value: item)
+            node.next = next
+            next.previous = node
+            node = next
+        }
     }
 }
 

Linked List/Tests/LinkedListTests.swift

@@ -336,4 +336,16 @@ class LinkedListTest: XCTestCase {
 
         XCTAssertTrue(value == 3)
     }
+
+    func testArrayInit() {
+        let testArray = Array(1...10_000)
+
+        let list = LinkedList(array: testArray)
+
+        XCTAssertEqual(list.head?.value, 1)
+        XCTAssertEqual(list.last?.value, 10_000)
+
+        XCTAssertEqual(list.count, 10_000)
+    }
+
 }