You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
hello-algo/zh-hant/codes/javascript/chapter_hashing/array_hash_map.js

129 lines
2.9 KiB

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

/**
* File: array_hash_map.js
* Created Time: 2022-12-26
* Author: Justin (xiefahit@gmail.com)
*/
/* 鍵值對 Number -> String */
class Pair {
constructor(key, val) {
this.key = key;
this.val = val;
}
}
/* 基於陣列實現的雜湊表 */
class ArrayHashMap {
#buckets;
constructor() {
// 初始化陣列,包含 100 個桶
this.#buckets = new Array(100).fill(null);
}
/* 雜湊函式 */
#hashFunc(key) {
return key % 100;
}
/* 查詢操作 */
get(key) {
let index = this.#hashFunc(key);
let pair = this.#buckets[index];
if (pair === null) return null;
return pair.val;
}
/* 新增操作 */
set(key, val) {
let index = this.#hashFunc(key);
this.#buckets[index] = new Pair(key, val);
}
/* 刪除操作 */
delete(key) {
let index = this.#hashFunc(key);
// 置為 null ,代表刪除
this.#buckets[index] = null;
}
/* 獲取所有鍵值對 */
entries() {
let arr = [];
for (let i = 0; i < this.#buckets.length; i++) {
if (this.#buckets[i]) {
arr.push(this.#buckets[i]);
}
}
return arr;
}
/* 獲取所有鍵 */
keys() {
let arr = [];
for (let i = 0; i < this.#buckets.length; i++) {
if (this.#buckets[i]) {
arr.push(this.#buckets[i].key);
}
}
return arr;
}
/* 獲取所有值 */
values() {
let arr = [];
for (let i = 0; i < this.#buckets.length; i++) {
if (this.#buckets[i]) {
arr.push(this.#buckets[i].val);
}
}
return arr;
}
/* 列印雜湊表 */
print() {
let pairSet = this.entries();
for (const pair of pairSet) {
console.info(`${pair.key} -> ${pair.val}`);
}
}
}
/* Driver Code */
/* 初始化雜湊表 */
const map = new ArrayHashMap();
/* 新增操作 */
// 在雜湊表中新增鍵值對 (key, value)
map.set(12836, '小哈');
map.set(15937, '小囉');
map.set(16750, '小算');
map.set(13276, '小法');
map.set(10583, '小鴨');
console.info('\n新增完成後雜湊表為\nKey -> Value');
map.print();
/* 查詢操作 */
// 向雜湊表中輸入鍵 key ,得到值 value
let name = map.get(15937);
console.info('\n輸入學號 15937 ,查詢到姓名 ' + name);
/* 刪除操作 */
// 在雜湊表中刪除鍵值對 (key, value)
map.delete(10583);
console.info('\n刪除 10583 後,雜湊表為\nKey -> Value');
map.print();
/* 走訪雜湊表 */
console.info('\n走訪鍵值對 Key->Value');
for (const pair of map.entries()) {
if (!pair) continue;
console.info(pair.key + ' -> ' + pair.val);
}
console.info('\n單獨走訪鍵 Key');
for (const key of map.keys()) {
console.info(key);
}
console.info('\n單獨走訪值 Value');
for (const val of map.values()) {
console.info(val);
}