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const formatDuration = ms => {if (ms < 0) ms = -ms;const time = {day: Math.floor(ms / 86400000),hour: Math.floor(ms / 3600000) % 24,minute: Math.floor(ms / 60000) % 60,second: Math.floor(ms / 1000) % 60,millisecond: Math.floor(ms) % 1000};return Object.entries(time).filter(val => val[1] !== 0).map(([key, val]) => `${val} ${key}${val !== 1 ? 's' : ''}`).join(', ');};formatDuration(1001); // '1 second, 1 millisecond'formatDuration(34325055574); // '397 days, 6 hours, 44 minutes, 15 seconds, 574 milliseconds'
class Graph {constructor(directed = true) {this.directed = directed;this.nodes = [];this.edges = new Map();}addNode(key, value = key) {this.nodes.push({ key, value });}addEdge(a, b, weight) {this.edges.set(JSON.stringify([a, b]), { a, b, weight });if (!this.directed)this.edges.set(JSON.stringify([b, a]), { a: b, b: a, weight });}removeNode(key) {this.nodes = this.nodes.filter(n => n.key !== key);[...this.edges.values()].forEach(({ a, b }) => {if (a === key || b === key) this.edges.delete(JSON.stringify([a, b]));});}removeEdge(a, b) {this.edges.delete(JSON.stringify([a, b]));if (!this.directed) this.edges.delete(JSON.stringify([b, a]));}findNode(key) {return this.nodes.find(x => x.key === key);}hasEdge(a, b) {return this.edges.has(JSON.stringify([a, b]));}setEdgeWeight(a, b, weight) {this.edges.set(JSON.stringify([a, b]), { a, b, weight });if (!this.directed)this.edges.set(JSON.stringify([b, a]), { a: b, b: a, weight });}getEdgeWeight(a, b) {return this.edges.get(JSON.stringify([a, b])).weight;}adjacent(key) {return [...this.edges.values()].reduce((acc, { a, b }) => {if (a === key) acc.push(b);return acc;}, []);}indegree(key) {return [...this.edges.values()].reduce((acc, { a, b }) => {if (b === key) acc++;return acc;}, 0);}outdegree(key) {return [...this.edges.values()].reduce((acc, { a, b }) => {if (a === key) acc++;return acc;}, 0);}}const g = new Graph();g.addNode('a');g.addNode('b');g.addNode('c');g.addNode('d');g.addEdge('a', 'c');g.addEdge('b', 'c');g.addEdge('c', 'b');g.addEdge('d', 'a');g.nodes.map(x => x.value); // ['a', 'b', 'c', 'd'][...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);// ['a => c', 'b => c', 'c => b', 'd => a']g.adjacent('c'); // ['b']g.indegree('c'); // 2g.outdegree('c'); // 1g.hasEdge('d', 'a'); // trueg.hasEdge('a', 'd'); // falseg.removeEdge('c', 'b');[...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);// ['a => c', 'b => c', 'd => a']g.removeNode('c');g.nodes.map(x => x.value); // ['a', 'b', 'd'][...g.edges.values()].map(({ a, b }) => `${a} => ${b}`);// ['d => a']g.setEdgeWeight('d', 'a', 5);g.getEdgeWeight('d', 'a'); // 5
var d = new Date();var d = new Date(milliseconds);var d = new Date(dateString);var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);
const levenshteinDistance = (s, t) => {if (!s.length) return t.length;if (!t.length) return s.length;const arr = [];for (let i = 0; i <= t.length; i++) {arr[i] = [i];for (let j = 1; j <= s.length; j++) {arr[i][j] =i === 0? j: Math.min(arr[i - 1][j] + 1,arr[i][j - 1] + 1,arr[i - 1][j - 1] + (s[j - 1] === t[i - 1] ? 0 : 1));}}return arr[t.length][s.length];};levenshteinDistance('duck', 'dark'); // 2
import { createSlice } from "@reduxjs/toolkit";const alert = createSlice({name: "alert",initialState: {msg: "",status: "",},reducers: {set_alert: (state, action) => {return {...state,msg: action.payload.msg,status: action.payload.status,};},clear_alert: (state, action) => {return {...state,msg: "",status: "",};},},});export default alert.reducer;const { set_alert, clear_alert } = alert.actions;export const setAlert = (msg, status) => dispatch => {dispatch(set_alert({ msg, status }));setTimeout(() => dispatch(clear_alert()), 4000);};export const clearAlert = () => dispatch => {dispatch(clear_alert());};
const unzipWith = (arr, fn) =>arr.reduce((acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),Array.from({length: Math.max(...arr.map(x => x.length))}).map(x => [])).map(val => fn(...val));unzipWith([[1, 10, 100],[2, 20, 200],],(...args) => args.reduce((acc, v) => acc + v, 0));// [3, 30, 300]