binomial coefficient
0 likes • Nov 19, 2022
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// There are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.// You are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:// The first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').// The second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').// For example, "R3G2B1" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.// Return the number of rods that have all three colors of rings on them.let rings = "B0B6G0R6R0R6G9";var countPoints = function(rings) {let sum = 0;// Always 10 Rodsfor (let i = 0; i < 10; i++) {if (rings.includes(`B${i}`) && rings.includes(`G${i}`) && rings.includes(`R${i}`)) {sum+=1;}}return sum;};console.log(countPoints(rings));
const Discord = require('discord.js');const client = new Discord.Client();const token = 'YOUR_BOT_TOKEN';// When the bot is ready, log a message to the consoleclient.on('ready', () => {console.log(`Logged in as ${client.user.tag}!`);});// When a user sends a message, check if they are authenticatedclient.on('message', async (msg) => {if (!msg.author.bot && !msg.author.authenticated) {const filter = (m) => m.author.id === msg.author.id;const collector = msg.channel.createMessageCollector(filter, { time: 15000 });// Send an authentication message to the usermsg.author.send('Please authenticate yourself by clicking this link: ' + generateAuthURL(msg.author.id));collector.on('collect', async (m) => {// Check if the message contains the authentication codeif (m.content.startsWith('!auth ')) {const code = m.content.slice(6);const { access_token } = await getAccessToken(code);// Set the user's authenticated status and access tokenmsg.author.authenticated = true;msg.author.access_token = access_token;collector.stop();}});collector.on('end', () => {if (!msg.author.authenticated) {msg.author.send('Authentication timed out.');}});}});// Generate an authentication URL for the userfunction generateAuthURL(userId) {const redirectURI = encodeURIComponent('YOUR_REDIRECT_URL');const scopes = 'identify';const clientID = 'YOUR_CLIENT_ID';return `https://discord.com/api/oauth2/authorize?client_id=${clientID}&redirect_uri=${redirectURI}&response_type=code&scope=${scopes}&state=${userId}`;}// Exchange the authorization code for an access tokenasync function getAccessToken(code) {const redirectURI = encodeURIComponent('YOUR_REDIRECT_URL');const clientID = 'YOUR_CLIENT_ID';const clientSecret = 'YOUR_CLIENT_SECRET';const res = await fetch('https://discord.com/api/oauth2/token', {method: 'POST',headers: {'Content-Type': 'application/x-www-form-urlencoded',},body: `grant_type=authorization_code&code=${code}&redirect_uri=${redirectURI}&client_id=${clientID}&client_secret=${clientSecret}`,});return await res.json();}client.login(token);
const formatDuration = ms => {if (ms < 0) ms = -ms;const time = {day: Math.floor(ms / 86400000),hour: Math.floor(ms / 3600000) % 24,minute: Math.floor(ms / 60000) % 60,second: Math.floor(ms / 1000) % 60,millisecond: Math.floor(ms) % 1000};return Object.entries(time).filter(val => val[1] !== 0).map(([key, val]) => `${val} ${key}${val !== 1 ? 's' : ''}`).join(', ');};formatDuration(1001); // '1 second, 1 millisecond'formatDuration(34325055574); // '397 days, 6 hours, 44 minutes, 15 seconds, 574 milliseconds'
"use strict";const nodemailer = require("nodemailer");// async..await is not allowed in global scope, must use a wrapperasync function main() {// Generate test SMTP service account from ethereal.email// Only needed if you don't have a real mail account for testinglet testAccount = await nodemailer.createTestAccount();// create reusable transporter object using the default SMTP transportlet transporter = nodemailer.createTransport({host: "smtp.ethereal.email",port: 587,secure: false, // true for 465, false for other portsauth: {user: testAccount.user, // generated ethereal userpass: testAccount.pass, // generated ethereal password},});// send mail with defined transport objectlet info = await transporter.sendMail({subject: "Hello ✔", // Subject linetext: "Hello world?", // plain text bodyhtml: "<b>Hello world?</b>", // html body});console.log("Message sent: %s", info.messageId);// Message sent: <[email protected]>// Preview only available when sending through an Ethereal accountconsole.log("Preview URL: %s", nodemailer.getTestMessageUrl(info));// Preview URL: https://ethereal.email/message/WaQKMgKddxQDoou...}main().catch(console.error);
const flat = arr => [].concat.apply([], arr.map(a => Array.isArray(a) ? flat(a) : a));// Orconst flat = arr => arr.reduce((a, b) => Array.isArray(b) ? [...a, ...flat(b)] : [...a, b], []);// Or// See the browser compatibility at https://caniuse.com/#feat=array-flatconst flat = arr => arr.flat();// Exampleflat(['cat', ['lion', 'tiger']]); // ['cat', 'lion', 'tiger']
const linearSearch = (arr, item) => {for (const i in arr) {if (arr[i] === item) return +i;}return -1;};linearSearch([2, 9, 9], 9); // 1linearSearch([2, 9, 9], 7); // -1