Merge branch 'krahets:master' into master

codes/swift/.gitignore

@@ -0,0 +1,130 @@
+# Created by https://www.toptal.com/developers/gitignore/api/objective-c,swift,swiftpackagemanager
+# Edit at https://www.toptal.com/developers/gitignore?templates=objective-c,swift,swiftpackagemanager
+
+### Objective-C ###
+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## User settings
+xcuserdata/
+
+## compatibility with Xcode 8 and earlier (ignoring not required starting Xcode 9)
+*.xcscmblueprint
+*.xccheckout
+
+## compatibility with Xcode 3 and earlier (ignoring not required starting Xcode 4)
+build/
+DerivedData/
+*.moved-aside
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+
+## Obj-C/Swift specific
+*.hmap
+
+## App packaging
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+# CocoaPods
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+# Pods/
+# Add this line if you want to avoid checking in source code from the Xcode workspace
+# *.xcworkspace
+
+# Carthage
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+# Carthage/Checkouts
+
+Carthage/Build/
+
+# fastlane
+# It is recommended to not store the screenshots in the git repo.
+# Instead, use fastlane to re-generate the screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://docs.fastlane.tools/best-practices/source-control/#source-control
+
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots/**/*.png
+fastlane/test_output
+
+# Code Injection
+# After new code Injection tools there's a generated folder /iOSInjectionProject
+# https://github.com/johnno1962/injectionforxcode
+
+iOSInjectionProject/
+
+### Objective-C Patch ###
+
+### Swift ###
+# Xcode
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+
+
+
+
+
+## Playgrounds
+timeline.xctimeline
+playground.xcworkspace
+
+# Swift Package Manager
+# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
+# Packages/
+# Package.pins
+# Package.resolved
+# *.xcodeproj
+# Xcode automatically generates this directory with a .xcworkspacedata file and xcuserdata
+# hence it is not needed unless you have added a package configuration file to your project
+# .swiftpm
+
+.build/
+
+# CocoaPods
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+# Pods/
+# Add this line if you want to avoid checking in source code from the Xcode workspace
+# *.xcworkspace
+
+# Carthage
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+# Carthage/Checkouts
+
+
+# Accio dependency management
+Dependencies/
+.accio/
+
+# fastlane
+# It is recommended to not store the screenshots in the git repo.
+# Instead, use fastlane to re-generate the screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://docs.fastlane.tools/best-practices/source-control/#source-control
+
+
+# Code Injection
+# After new code Injection tools there's a generated folder /iOSInjectionProject
+# https://github.com/johnno1962/injectionforxcode
+
+
+### SwiftPackageManager ###
+Packages
+xcuserdata
+*.xcodeproj
+
+
+# End of https://www.toptal.com/developers/gitignore/api/objective-c,swift,swiftpackagemanager

codes/swift/Package.swift

@@ -0,0 +1,18 @@
+// swift-tools-version: 5.7
+
+import PackageDescription
+
+let package = Package(
+    name: "HelloAlgo",
+    products: [
+        .executable(name: "time_complexity", targets: ["time_complexity"]),
+        .executable(name: "worst_best_time_complexity", targets: ["worst_best_time_complexity"]),
+        .executable(name: "space_complexity", targets: ["space_complexity"]),
+    ],
+    targets: [
+        .target(name: "utils", path: "utils"),
+        .executableTarget(name: "time_complexity", path: "chapter_computational_complexity", sources: ["time_complexity.swift"]),
+        .executableTarget(name: "worst_best_time_complexity", path: "chapter_computational_complexity", sources: ["worst_best_time_complexity.swift"]),
+        .executableTarget(name: "space_complexity", dependencies: ["utils"], path: "chapter_computational_complexity", sources: ["space_complexity.swift"]),
+    ]
+)

codes/swift/chapter_computational_complexity/space_complexity.swift

@@ -0,0 +1,98 @@
+/*
+ * File: space_complexity.swift
+ * Created Time: 2023-01-01
+ * Author: nuomi1 ([email protected])
+ */
+
+import utils
+
+// 函数
+@discardableResult
+func function() -> Int {
+    // do something
+    return 0
+}
+
+// 常数阶
+func constant(n: Int) {
+    // 常量、变量、对象占用 O(1) 空间
+    let a = 0
+    var b = 0
+    let nums = Array(repeating: 0, count: 10000)
+    let node = ListNode(x: 0)
+    // 循环中的变量占用 O(1) 空间
+    for _ in 0 ..< n {
+        let c = 0
+    }
+    // 循环中的函数占用 O(1) 空间
+    for _ in 0 ..< n {
+        function()
+    }
+}
+
+// 线性阶
+func linear(n: Int) {
+    // 长度为 n 的数组占用 O(n) 空间
+    let nums = Array(repeating: 0, count: n)
+    // 长度为 n 的列表占用 O(n) 空间
+    let nodes = (0 ..< n).map { ListNode(x: $0) }
+    // 长度为 n 的哈希表占用 O(n) 空间
+    let map = Dictionary(uniqueKeysWithValues: (0 ..< n).map { ($0, "\($0)") })
+}
+
+// 线性阶（递归实现）
+func linearRecur(n: Int) {
+    print("递归 n = \(n)")
+    if n == 1 {
+        return
+    }
+    linearRecur(n: n - 1)
+}
+
+// 平方阶
+func quadratic(n: Int) {
+    // 二维列表占用 O(n^2) 空间
+    let numList = Array(repeating: Array(repeating: 0, count: n), count: n)
+}
+
+// 平方阶（递归实现）
+@discardableResult
+func quadraticRecur(n: Int) -> Int {
+    if n <= 0 {
+        return 0
+    }
+    // 数组 nums 长度为 n, n-1, ..., 2, 1
+    let nums = Array(repeating: 0, count: n)
+    print("递归 n = \(n) 中的 nums 长度 = \(nums.count)")
+    return quadraticRecur(n: n - 1)
+}
+
+// 指数阶（建立满二叉树）
+func buildTree(n: Int) -> TreeNode? {
+    if n == 0 {
+        return nil
+    }
+    let root = TreeNode(x: 0)
+    root.left = buildTree(n: n - 1)
+    root.right = buildTree(n: n - 1)
+    return root
+}
+
+@main
+enum SpaceComplexity {
+    // Driver Code
+    static func main() {
+        let n = 5
+        // 常数阶
+        constant(n: n)
+        // 线性阶
+        linear(n: n)
+        linearRecur(n: n)
+        // 平方阶
+        quadratic(n: n)
+        quadraticRecur(n: n)
+        // 指数阶
+        let root = buildTree(n: n)
+        PrintUtil.printTree(root: root)
+    }
+}

codes/swift/chapter_computational_complexity/time_complexity.swift

@@ -131,40 +131,41 @@ func factorialRecur(n: Int) -> Int {
     return count
 }
 
-func main() {
-    // 可以修改 n 运行，体会一下各种复杂度的操作数量变化趋势
-    let n = 8
-    print("输入数据大小 n =", n)
-
-    var count = constant(n: n)
-    print("常数阶的计算操作数量 =", count)
-
-    count = linear(n: n)
-    print("线性阶的计算操作数量 =", count)
-    count = arrayTraversal(nums: Array(repeating: 0, count: n))
-    print("线性阶（遍历数组）的计算操作数量 =", count)
-
-    count = quadratic(n: n)
-    print("平方阶的计算操作数量 =", count)
-    var nums = Array(sequence(first: n, next: { $0 > 0 ? $0 - 1 : nil })) // [n,n-1,...,2,1]
-    count = bubbleSort(nums: &nums)
-    print("平方阶（冒泡排序）的计算操作数量 =", count)
-
-    count = exponential(n: n)
-    print("指数阶（循环实现）的计算操作数量 =", count)
-    count = expRecur(n: n)
-    print("指数阶（递归实现）的计算操作数量 =", count)
-
-    count = logarithmic(n: n)
-    print("对数阶（循环实现）的计算操作数量 =", count)
-    count = logRecur(n: n)
-    print("对数阶（递归实现）的计算操作数量 =", count)
-
-    count = linearLogRecur(n: Double(n))
-    print("线性对数阶（递归实现）的计算操作数量 =", count)
-
-    count = factorialRecur(n: n)
-    print("阶乘阶（递归实现）的计算操作数量 =", count)
+@main
+enum TimeComplexity {
+    static func main() {
+        // 可以修改 n 运行，体会一下各种复杂度的操作数量变化趋势
+        let n = 8
+        print("输入数据大小 n =", n)
+
+        var count = constant(n: n)
+        print("常数阶的计算操作数量 =", count)
+
+        count = linear(n: n)
+        print("线性阶的计算操作数量 =", count)
+        count = arrayTraversal(nums: Array(repeating: 0, count: n))
+        print("线性阶（遍历数组）的计算操作数量 =", count)
+
+        count = quadratic(n: n)
+        print("平方阶的计算操作数量 =", count)
+        var nums = Array(sequence(first: n, next: { $0 > 0 ? $0 - 1 : nil })) // [n,n-1,...,2,1]
+        count = bubbleSort(nums: &nums)
+        print("平方阶（冒泡排序）的计算操作数量 =", count)
+
+        count = exponential(n: n)
+        print("指数阶（循环实现）的计算操作数量 =", count)
+        count = expRecur(n: n)
+        print("指数阶（递归实现）的计算操作数量 =", count)
+
+        count = logarithmic(n: n)
+        print("对数阶（循环实现）的计算操作数量 =", count)
+        count = logRecur(n: n)
+        print("对数阶（递归实现）的计算操作数量 =", count)
+
+        count = linearLogRecur(n: Double(n))
+        print("线性对数阶（递归实现）的计算操作数量 =", count)
+
+        count = factorialRecur(n: n)
+        print("阶乘阶（递归实现）的计算操作数量 =", count)
+    }
 }
-
-main()

codes/swift/chapter_computational_complexity/worst_best_time_complexity.swift

@@ -23,15 +23,16 @@ func findOne(nums: [Int]) -> Int {
     return -1
 }
 
-// Driver Code
-func main() {
-    for _ in 0 ..< 10 {
-        let n = 100
-        let nums = randomNumbers(n: n)
-        let index = findOne(nums: nums)
-        print("数组 [ 1, 2, ..., n ] 被打乱后 =", nums)
-        print("数字 1 的索引为", index)
+@main
+enum WorstBestTimeComplexity {
+    // Driver Code
+    static func main() {
+        for _ in 0 ..< 10 {
+            let n = 100
+            let nums = randomNumbers(n: n)
+            let index = findOne(nums: nums)
+            print("数组 [ 1, 2, ..., n ] 被打乱后 =", nums)
+            print("数字 1 的索引为", index)
+        }
     }
 }
-
-main()

codes/swift/utils/ListNode.swift

@@ -0,0 +1,14 @@
+/*
+ * File: ListNode.swift
+ * Created Time: 2023-01-02
+ * Author: nuomi1 ([email protected])
+ */
+
+public class ListNode {
+    public var val: Int // 结点值
+    public var next: ListNode? // 后继结点引用
+
+    public init(x: Int) {
+        val = x
+    }
+}