• Nov 19, 2022 •CodeCatch
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const heapsort = arr => { const a = [...arr]; let l = a.length; const heapify = (a, i) => { const left = 2 * i + 1; const right = 2 * i + 2; let max = i; if (left < l && a[left] > a[max]) max = left; if (right < l && a[right] > a[max]) max = right; if (max !== i) { [a[max], a[i]] = [a[i], a[max]]; heapify(a, max); } }; for (let i = Math.floor(l / 2); i >= 0; i -= 1) heapify(a, i); for (i = a.length - 1; i > 0; i--) { [a[0], a[i]] = [a[i], a[0]]; l--; heapify(a, 0); } return a; }; heapsort([6, 3, 4, 1]); // [1, 3, 4, 6]
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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]
• Mar 11, 2021 •C S
const mongoose = require('mongoose') const UserSchema = new mongoose.Schema({ username: { type: String, required: true }, email: { type: String, unique: true, required: true }, password: { type: String, required: true }, date: { type: Date, default: Date.now } }) module.exports = User = mongoose.model('user', UserSchema)
// 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 Rods for (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));
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const jwt = require("jsonwebtoken"); const authToken = (req, res, next) => { const token = req.headers["x-auth-token"]; try { req.user = jwt.verify(token, process.env.ACCESS_TOKEN_SECRET); next(); } catch (err) { console.log(err.message); res.status(401).json({ msg: "Error authenticating token" }); } }; module.exports = authToken;
const reverse = str => str.split('').reverse().join(''); reverse('hello world'); // Result: 'dlrow olleh'