[swift] [05_array] [add]

swift/05_array/MyArray.swift

@@ -0,0 +1,77 @@
+//
+// Created by Jiandan on 2018/10/10.
+// Copyright (c) 2018 Jiandan. All rights reserved.
+//
+
+import Foundation
+
+// <Element> Swift 泛型，此数组支持不同数据类型
+public struct MyArray<Element> {
+    private var data: [Element]
+    private var capacity = 0 // 数组长度
+    private var count = 0 // 已保存的数据个数
+
+    /// 构造方法
+    /// - parameter defaultElement: 默认元素，用来占位
+    /// - parameter capacity: 数组长度
+    init(defaultElement: Element, capacity: Int) {
+        data = [Element](repeating: defaultElement, count: capacity)
+        self.capacity = capacity
+    }
+
+    // 根据 index，查找元素
+    func find(at index: Int) -> Element? {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count else {
+            return nil
+        }
+
+        return data[index]
+    }
+
+    // 根据 index，删除元素
+    mutating func delete(at index: Int) -> Bool {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count else {
+            return false
+        }
+
+        // [index, count - 1) 从 index 开始，元素分别向前移动一位
+        for i in index ..< count - 1 {
+            data[i] = data[i+1]
+        }
+        count -= 1
+        return true
+    }
+
+    // 根据 index 插入元素
+    mutating func insert(value: Element, at index: Int) -> Bool {
+        // index 必须在 [0, count)
+        guard index >= 0, index < count, count < capacity else {
+            return false
+        }
+
+        // count - 1 ~ index
+        for i in (index ... count - 1).reversed() {
+            data[i + 1] = data[i]
+        }
+
+        data[index] = value
+        count += 1
+        return true
+    }
+
+    // 添加元素
+    mutating func add(value: Element) -> Bool {
+        guard count < capacity else {
+            return false
+        }
+        data[count] = value
+        count += 1
+        return true
+    }
+
+    func printAll() {
+        print("\(data)")
+    }
+}