[swift][09_queue][remove] Remove "typealias Element = T".

[swift][09_queue][fix] Fix "size" in "QueueBasedOnLinkedList".
YuanLianDu · Oct 13, 2018 · e121c38 · e121c38
1 parent fc167fd
commit e121c38
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Showing 3 changed files with 10 additions and 22 deletions.
diff --git a/swift/09_queue/ArrayQueue.swift b/swift/09_queue/ArrayQueue.swift
@@ -6,9 +6,7 @@
 import Foundation
 
 /// 用数组实现的队列
-struct ArrayQueue<T>: Queue {
-    typealias Element = T
-
+struct ArrayQueue<Element>: Queue {
     /// 数组
     private var items: [Element]
     /// 数组最大长度
@@ -78,9 +76,7 @@ struct ArrayQueue<T>: Queue {
 
 /// 使用2个数组实现无界队列，用到 Swift 中 Array 较多的方法
 /// 来源：《iOS 面试之道》（故胤道长，唐巧）
-struct ArrayQueue2<T>: Queue {
-    typealias Element = T
-
+struct ArrayQueue2<Element>: Queue {
     /// 输入数组，主要负责入队
     var inArray = [Element]()
     /// 输出数组，主要负责出队

diff --git a/swift/09_queue/CircularQueue.swift b/swift/09_queue/CircularQueue.swift
@@ -6,9 +6,7 @@
 import Foundation
 
 /// 循环队列
-struct CircularQueue<T>: Queue {
-    typealias Element = T
-
+struct CircularQueue<Element>: Queue {
     /// 数组
     private var items: [Element]
     /// 数组最大长度

diff --git a/swift/09_queue/QueueBasedOnLinkedList.swift b/swift/09_queue/QueueBasedOnLinkedList.swift
@@ -5,18 +5,7 @@
 
 import Foundation
 
-class Node<T> {
-    var value: T?
-    var next: Node?
-
-    init(value: T) {
-        self.value = value
-    }
-}
-
-struct QueueBasedOnLinkedList<T>: Queue {
-    typealias Element = T
-
+struct QueueBasedOnLinkedList<Element>: Queue {
     /// 队首
     var head: Node<Element>?
     /// 队尾
@@ -27,10 +16,15 @@ struct QueueBasedOnLinkedList<T>: Queue {
     var isEmpty: Bool { return head == nil }
 
     var size: Int {
-        var count = 0
+        if isEmpty {
+            return 0
+        }
+
+        var count = 1 // head 本身算一个
         while head?.next != nil {
             count += 1
         }
+
         return count
     }