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feat: add Swift codes for backtracking_algorithm article (#480)

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* fix: compile error

* fix: package define

* feat: add Swift codes for backtracking_algorithm article
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nuomi1 2023-05-03 18:45:43 +08:00 committed by GitHub
parent ca76336a55
commit 561ef20462
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 241 additions and 6 deletions
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20
codes/swift/Package.swift
View file

@ -9,7 +9,6 @@ let package = Package(
.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"]),
.executable(name: "leetcode_two_sum", targets: ["leetcode_two_sum"]),
// chapter_array_and_linkedlist
.executable(name: "array", targets: ["array"]),
.executable(name: "linked_list", targets: ["linked_list"]),
@ -25,6 +24,8 @@ let package = Package(
.executable(name: "deque", targets: ["deque"]),
.executable(name: "linkedlist_deque", targets: ["linkedlist_deque"]),
.executable(name: "array_deque", targets: ["array_deque"]),
// chapter_binary_search
.executable(name: "binary_search", targets: ["binary_search"]),
// chapter_hashing
.executable(name: "hash_map", targets: ["hash_map"]),
.executable(name: "array_hash_map", targets: ["array_hash_map"]),
@ -42,8 +43,8 @@ let package = Package(
.executable(name: "graph_bfs", targets: ["graph_bfs"]),
.executable(name: "graph_dfs", targets: ["graph_dfs"]),
// chapter_searching
.executable(name: "leetcode_two_sum", targets: ["leetcode_two_sum"]),
.executable(name: "linear_search", targets: ["linear_search"]),
.executable(name: "binary_search", targets: ["binary_search"]),
.executable(name: "hashing_search", targets: ["hashing_search"]),
// chapter_sorting
.executable(name: "bubble_sort", targets: ["bubble_sort"]),
@ -53,6 +54,11 @@ let package = Package(
.executable(name: "bucket_sort", targets: ["bucket_sort"]),
.executable(name: "counting_sort", targets: ["counting_sort"]),
.executable(name: "radix_sort", targets: ["radix_sort"]),
// chapter_backtracking
.executable(name: "preorder_traversal_i_compact", targets: ["preorder_traversal_i_compact"]),
.executable(name: "preorder_traversal_ii_compact", targets: ["preorder_traversal_ii_compact"]),
.executable(name: "preorder_traversal_iii_compact", targets: ["preorder_traversal_iii_compact"]),
.executable(name: "preorder_traversal_iii_template", targets: ["preorder_traversal_iii_template"]),
],
targets: [
// helper
@ -62,7 +68,6 @@ let package = Package(
.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"]),
.executableTarget(name: "leetcode_two_sum", path: "chapter_computational_complexity", sources: ["leetcode_two_sum.swift"]),
// chapter_array_and_linkedlist
.executableTarget(name: "array", path: "chapter_array_and_linkedlist", sources: ["array.swift"]),
.executableTarget(name: "linked_list", dependencies: ["utils"], path: "chapter_array_and_linkedlist", sources: ["linked_list.swift"]),
@ -78,6 +83,8 @@ let package = Package(
.executableTarget(name: "deque", path: "chapter_stack_and_queue", sources: ["deque.swift"]),
.executableTarget(name: "linkedlist_deque", path: "chapter_stack_and_queue", sources: ["linkedlist_deque.swift"]),
.executableTarget(name: "array_deque", path: "chapter_stack_and_queue", sources: ["array_deque.swift"]),
// chapter_binary_search
.executableTarget(name: "binary_search", path: "chapter_binary_search", sources: ["binary_search.swift"]),
// chapter_hashing
.executableTarget(name: "hash_map", dependencies: ["utils"], path: "chapter_hashing", sources: ["hash_map.swift"]),
.executableTarget(name: "array_hash_map", path: "chapter_hashing", sources: ["array_hash_map.swift"]),
@ -95,8 +102,8 @@ let package = Package(
.executableTarget(name: "graph_bfs", dependencies: ["utils", "graph_adjacency_list_target"], path: "chapter_graph", sources: ["graph_bfs.swift"]),
.executableTarget(name: "graph_dfs", dependencies: ["utils", "graph_adjacency_list_target"], path: "chapter_graph", sources: ["graph_dfs.swift"]),
// chapter_searching
.executableTarget(name: "leetcode_two_sum", path: "chapter_searching", sources: ["leetcode_two_sum.swift"]),
.executableTarget(name: "linear_search", dependencies: ["utils"], path: "chapter_searching", sources: ["linear_search.swift"]),
.executableTarget(name: "binary_search", path: "chapter_searching", sources: ["binary_search.swift"]),
.executableTarget(name: "hashing_search", dependencies: ["utils"], path: "chapter_searching", sources: ["hashing_search.swift"]),
// chapter_sorting
.executableTarget(name: "bubble_sort", path: "chapter_sorting", sources: ["bubble_sort.swift"]),
@ -106,5 +113,10 @@ let package = Package(
.executableTarget(name: "bucket_sort", path: "chapter_sorting", sources: ["bucket_sort.swift"]),
.executableTarget(name: "counting_sort", path: "chapter_sorting", sources: ["counting_sort.swift"]),
.executableTarget(name: "radix_sort", path: "chapter_sorting", sources: ["radix_sort.swift"]),
// chapter_backtracking
.executableTarget(name: "preorder_traversal_i_compact", dependencies: ["utils"], path: "chapter_backtracking", sources: ["preorder_traversal_i_compact.swift"]),
.executableTarget(name: "preorder_traversal_ii_compact", dependencies: ["utils"], path: "chapter_backtracking", sources: ["preorder_traversal_ii_compact.swift"]),
.executableTarget(name: "preorder_traversal_iii_compact", dependencies: ["utils"], path: "chapter_backtracking", sources: ["preorder_traversal_iii_compact.swift"]),
.executableTarget(name: "preorder_traversal_iii_template", dependencies: ["utils"], path: "chapter_backtracking", sources: ["preorder_traversal_iii_template.swift"]),
]
)

43
codes/swift/chapter_backtracking/preorder_traversal_i_compact.swift Normal file
View file

@ -0,0 +1,43 @@
/**
* File: preorder_traversal_i_compact.swift
* Created Time: 2023-04-30
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
var res: [TreeNode] = []
/* 前序遍历：例题一 */
func preOrder(root: TreeNode?) {
guard let root = root else {
return
}
if root.val == 7 {
// 记录解
res.append(root)
}
preOrder(root: root.left)
preOrder(root: root.right)
}
@main
enum PreorderTraversalICompact {
/* Driver Code */
static func main() {
let root = TreeNode.listToTree(list: [1, 7, 3, 4, 5, 6, 7])
print("\n初始化二叉树")
PrintUtil.printTree(root: root)
// 前序遍历
res = []
preOrder(root: root)
print("\n输出所有值为 7 的节点")
var vals: [Int] = []
for node in res {
vals.append(node.val)
}
print(vals)
}
}

51
codes/swift/chapter_backtracking/preorder_traversal_ii_compact.swift Normal file
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@ -0,0 +1,51 @@
/**
* File: preorder_traversal_ii_compact.swift
* Created Time: 2023-04-30
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
var path: [TreeNode] = []
var res: [[TreeNode]] = []
/* 前序遍历：例题二 */
func preOrder(root: TreeNode?) {
guard let root = root else {
return
}
// 尝试
path.append(root)
if root.val == 7 {
// 记录解
res.append(path)
}
preOrder(root: root.left)
preOrder(root: root.right)
// 回退
path.removeLast()
}
@main
enum PreorderTraversalIICompact {
/* Driver Code */
static func main() {
let root = TreeNode.listToTree(list: [1, 7, 3, 4, 5, 6, 7])
print("\n初始化二叉树")
PrintUtil.printTree(root: root)
// 前序遍历
path = []
res = []
preOrder(root: root)
print("\n输出所有根节点到节点 7 的路径")
for path in res {
var vals: [Int] = []
for node in path {
vals.append(node.val)
}
print(vals)
}
}
}

52
codes/swift/chapter_backtracking/preorder_traversal_iii_compact.swift Normal file
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@ -0,0 +1,52 @@
/**
* File: preorder_traversal_iii_compact.swift
* Created Time: 2023-04-30
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
var path: [TreeNode] = []
var res: [[TreeNode]] = []
/* 前序遍历：例题三 */
func preOrder(root: TreeNode?) {
// 剪枝
guard let root = root, root.val != 3 else {
return
}
// 尝试
path.append(root)
if root.val == 7 {
// 记录解
res.append(path)
}
preOrder(root: root.left)
preOrder(root: root.right)
// 回退
path.removeLast()
}
@main
enum PreorderTraversalIIICompact {
/* Driver Code */
static func main() {
let root = TreeNode.listToTree(list: [1, 7, 3, 4, 5, 6, 7])
print("\n初始化二叉树")
PrintUtil.printTree(root: root)
// 前序遍历
path = []
res = []
preOrder(root: root)
print("\n输出所有根节点到节点 7 的路径，且路径中不包含值为 3 的节点")
for path in res {
var vals: [Int] = []
for node in path {
vals.append(node.val)
}
print(vals)
}
}
}

77
codes/swift/chapter_backtracking/preorder_traversal_iii_template.swift Normal file
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@ -0,0 +1,77 @@
/**
* File: preorder_traversal_iii_template.swift
* Created Time: 2023-04-30
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
/* 判断当前状态是否为解 */
func isSolution(state: [TreeNode]) -> Bool {
!state.isEmpty && state.last!.val == 7
}
/* 记录解 */
func recordSolution(state: [TreeNode], res: inout [[TreeNode]]) {
res.append(state)
}
/* 判断在当前状态下，该选择是否合法 */
func isValid(state: [TreeNode], choice: TreeNode?) -> Bool {
choice != nil && choice!.val != 3
}
/* 更新状态 */
func makeChoice(state: inout [TreeNode], choice: TreeNode) {
state.append(choice)
}
/* 恢复状态 */
func undoChoice(state: inout [TreeNode], choice: TreeNode) {
state.removeLast()
}
/* 回溯算法：例题三 */
func backtrack(state: inout [TreeNode], choices: [TreeNode], res: inout [[TreeNode]]) {
// 检查是否为解
if isSolution(state: state) {
recordSolution(state: state, res: &res)
return
}
// 遍历所有选择
for choice in choices {
// 剪枝：检查选择是否合法
if isValid(state: state, choice: choice) {
// 尝试：做出选择，更新状态
makeChoice(state: &state, choice: choice)
// 进行下一轮选择
backtrack(state: &state, choices: [choice.left, choice.right].compactMap { $0 }, res: &res)
// 回退：撤销选择，恢复到之前的状态
undoChoice(state: &state, choice: choice)
}
}
}
@main
enum preorder_traversal_iii_template {
/* Driver Code */
static func main() {
let root = TreeNode.listToTree(list: [1, 7, 3, 4, 5, 6, 7])
print("\n初始化二叉树")
PrintUtil.printTree(root: root)
// 回溯算法
var state: [TreeNode] = []
var res: [[TreeNode]] = []
backtrack(state: &state, choices: [root].compactMap { $0 }, res: &res)
print("\n输出所有根节点到节点 7 的路径，且路径中不包含值为 3 的节点")
for path in res {
var vals: [Int] = []
for node in path {
vals.append(node.val)
}
print(vals)
}
}
}

2
codes/swift/chapter_tree/avl_tree.swift
View file

@ -145,7 +145,7 @@ class AVLTree {
}
} else {
// 子节点数量 = 2 ，则将中序遍历的下个节点删除，并用该节点替换当前节点
let temp = node?.right
var temp = node?.right
while temp?.left != nil {
temp = temp?.left
}

2
codes/swift/chapter_tree/binary_search_tree.swift
View file

@ -132,7 +132,7 @@ class BinarySearchTree {
// 子节点数量 = 2
else {
// 获取中序遍历中 cur 的下一个节点
let tmp = cur?.right
var tmp = cur?.right
while tmp?.left != nil {
tmp = tmp?.left
}