feat: add Swift codes for hash_map article

pull/266/head
nuomi1 2 years ago
parent a01841a20c
commit f0c54abb9a
No known key found for this signature in database
GPG Key ID: E410D5FF602FBF25

@ -20,6 +20,8 @@ let package = Package(
.executable(name: "linkedlist_queue", targets: ["linkedlist_queue"]), .executable(name: "linkedlist_queue", targets: ["linkedlist_queue"]),
.executable(name: "array_queue", targets: ["array_queue"]), .executable(name: "array_queue", targets: ["array_queue"]),
.executable(name: "deque", targets: ["deque"]), .executable(name: "deque", targets: ["deque"]),
.executable(name: "hash_map", targets: ["hash_map"]),
.executable(name: "array_hash_map", targets: ["array_hash_map"]),
], ],
targets: [ targets: [
.target(name: "utils", path: "utils"), .target(name: "utils", path: "utils"),
@ -38,5 +40,7 @@ let package = Package(
.executableTarget(name: "linkedlist_queue", dependencies: ["utils"], path: "chapter_stack_and_queue", sources: ["linkedlist_queue.swift"]), .executableTarget(name: "linkedlist_queue", dependencies: ["utils"], path: "chapter_stack_and_queue", sources: ["linkedlist_queue.swift"]),
.executableTarget(name: "array_queue", path: "chapter_stack_and_queue", sources: ["array_queue.swift"]), .executableTarget(name: "array_queue", path: "chapter_stack_and_queue", sources: ["array_queue.swift"]),
.executableTarget(name: "deque", path: "chapter_stack_and_queue", sources: ["deque.swift"]), .executableTarget(name: "deque", path: "chapter_stack_and_queue", sources: ["deque.swift"]),
.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"]),
] ]
) )

@ -0,0 +1,139 @@
/**
* File: array_hash_map.swift
* Created Time: 2023-01-16
* Author: nuomi1 (nuomi1@qq.com)
*/
/* int->String */
class Entry {
var key: Int
var val: String
init(key: Int, val: String) {
self.key = key
self.val = val
}
}
/* */
class ArrayHashMap {
private var bucket: [Entry?] = []
init() {
// 100
for _ in 0 ..< 100 {
bucket.append(nil)
}
}
/* */
private func hashFunc(key: Int) -> Int {
let index = key % 100
return index
}
/* */
func get(key: Int) -> String? {
let index = hashFunc(key: key)
let pair = bucket[index]
return pair?.val
}
/* */
func put(key: Int, val: String) {
let pair = Entry(key: key, val: val)
let index = hashFunc(key: key)
bucket[index] = pair
}
/* */
func remove(key: Int) {
let index = hashFunc(key: key)
// nil
bucket[index] = nil
}
/* */
func entrySet() -> [Entry] {
var entrySet: [Entry] = []
for pair in bucket {
if let pair = pair {
entrySet.append(pair)
}
}
return entrySet
}
/* */
func keySet() -> [Int] {
var keySet: [Int] = []
for pair in bucket {
if let pair = pair {
keySet.append(pair.key)
}
}
return keySet
}
/* */
func valueSet() -> [String] {
var valueSet: [String] = []
for pair in bucket {
if let pair = pair {
valueSet.append(pair.val)
}
}
return valueSet
}
/* */
func print() {
for entry in entrySet() {
Swift.print("\(entry.key) -> \(entry.val)")
}
}
}
@main
enum _ArrayHashMap {
/* Driver Code */
static func main() {
/* */
let map = ArrayHashMap()
/* */
// (key, value)
map.put(key: 12836, val: "小哈")
map.put(key: 15937, val: "小啰")
map.put(key: 16750, val: "小算")
map.put(key: 13276, val: "小法")
map.put(key: 10583, val: "小鸭")
print("\n添加完成后,哈希表为\nKey -> Value")
map.print()
/* */
// key value
let name = map.get(key: 15937)!
print("\n输入学号 15937 ,查询到姓名 \(name)")
/* */
// (key, value)
map.remove(key: 10583)
print("\n删除 10583 后,哈希表为\nKey -> Value")
map.print()
/* */
print("\n遍历键值对 Key->Value")
for entry in map.entrySet() {
print("\(entry.key) -> \(entry.val)")
}
print("\n单独遍历键 Key")
for key in map.keySet() {
print(key)
}
print("\n单独遍历值 Value")
for val in map.valueSet() {
print(val)
}
}
}

@ -0,0 +1,51 @@
/**
* File: hash_map.swift
* Created Time: 2023-01-16
* Author: nuomi1 (nuomi1@qq.com)
*/
import utils
@main
enum HashMap {
/* Driver Code */
static func main() {
/* */
var map: [Int: String] = [:]
/* */
// (key, value)
map[12836] = "小哈"
map[15937] = "小啰"
map[16750] = "小算"
map[13276] = "小法"
map[10583] = "小鸭"
print("\n添加完成后,哈希表为\nKey -> Value")
PrintUtil.printHashMap(map: map)
/* */
// key value
let name = map[15937]!
print("\n输入学号 15937 ,查询到姓名 \(name)")
/* */
// (key, value)
map.removeValue(forKey: 10583)
print("\n删除 10583 后,哈希表为\nKey -> Value")
PrintUtil.printHashMap(map: map)
/* */
print("\n遍历键值对 Key->Value")
for (key, value) in map {
print("\(key) -> \(value)")
}
print("\n单独遍历键 Key")
for key in map.keys {
print(key)
}
print("\n单独遍历值 Value")
for value in map.values {
print(value)
}
}
}

@ -68,4 +68,10 @@ public enum PrintUtil {
showTrunks(p: p?.prev) showTrunks(p: p?.prev)
print(p!.str, terminator: "") print(p!.str, terminator: "")
} }
public static func printHashMap<K, V>(map: [K: V]) {
for (key, value) in map {
print("\(key) -> \(value)")
}
}
} }

@ -210,7 +210,24 @@ comments: true
=== "Swift" === "Swift"
```swift title="hash_map.swift" ```swift title="hash_map.swift"
/* 初始化哈希表 */
var map: [Int: String] = [:]
/* 添加操作 */
// 在哈希表中添加键值对 (key, value)
map[12836] = "小哈"
map[15937] = "小啰"
map[16750] = "小算"
map[13276] = "小法"
map[10583] = "小鸭"
/* 查询操作 */
// 向哈希表输入键 key ,得到值 value
let name = map[15937]!
/* 删除操作 */
// 在哈希表中删除键值对 (key, value)
map.removeValue(forKey: 10583)
``` ```
遍历哈希表有三种方式,即 **遍历键值对、遍历键、遍历值**。 遍历哈希表有三种方式,即 **遍历键值对、遍历键、遍历值**。
@ -348,7 +365,19 @@ comments: true
=== "Swift" === "Swift"
```swift title="hash_map.swift" ```swift title="hash_map.swift"
/* 遍历哈希表 */
// 遍历键值对 Key->Value
for (key, value) in map {
print("\(key) -> \(value)")
}
// 单独遍历键 Key
for key in map.keys {
print(key)
}
// 单独遍历值 Value
for value in map.values {
print(value)
}
``` ```
## 哈希函数 ## 哈希函数
@ -771,7 +800,55 @@ $$
=== "Swift" === "Swift"
```swift title="array_hash_map.swift" ```swift title="array_hash_map.swift"
/* 键值对 int->String */
class Entry {
var key: Int
var val: String
init(key: Int, val: String) {
self.key = key
self.val = val
}
}
/* 基于数组简易实现的哈希表 */
class ArrayHashMap {
private var bucket: [Entry?] = []
init() {
// 初始化一个长度为 100 的桶(数组)
for _ in 0 ..< 100 {
bucket.append(nil)
}
}
/* 哈希函数 */
private func hashFunc(key: Int) -> Int {
let index = key % 100
return index
}
/* 查询操作 */
func get(key: Int) -> String? {
let index = hashFunc(key: key)
let pair = bucket[index]
return pair?.val
}
/* 添加操作 */
func put(key: Int, val: String) {
let pair = Entry(key: key, val: val)
let index = hashFunc(key: key)
bucket[index] = pair
}
/* 删除操作 */
func remove(key: Int) {
let index = hashFunc(key: key)
// 置为 nil ,代表删除
bucket[index] = nil
}
}
``` ```
## 哈希冲突 ## 哈希冲突

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