• Oct 15, 2022 •CodeCatch
3 likes • 4 views
const MongoClient = require('mongodb').MongoClient; const assert = require('assert'); // Connection URL const url = 'mongodb://localhost:27017'; // Database Name const dbName = 'myproject'; // Use connect method to connect to the server MongoClient.connect(url, function(err, client) { assert.equal(null, err); console.log("Connected successfully to server"); const db = client.db(dbName); client.close(); });
• Nov 19, 2022 •CodeCatch
0 likes • 0 views
// promisify(f, true) to get array of results function promisify(f, manyArgs = false) { return function (...args) { return new Promise((resolve, reject) => { function callback(err, ...results) { // our custom callback for f if (err) { reject(err); } else { // resolve with all callback results if manyArgs is specified resolve(manyArgs ? results : results[0]); } } args.push(callback); f.call(this, ...args); }); }; } // usage: f = promisify(f, true); f(...).then(arrayOfResults => ..., err => ...);
• Mar 22, 2022 •LeifMessinger
0 likes • 2 views
//QM Helper by Leif Messinger //Groups numbers by number of bits and shows their binary representations. //To be used on x.com const minterms = prompt("Enter your minterms separated by commas").split(",").map(x => parseInt(x.trim())); const maxNumBits = minterms.reduce(function(a, b) { return Math.max(a, Math.log2(b)); }); const bitGroups = []; for(let i = 0; i < maxNumBits; ++i){ bitGroups.push([]); } for(const minterm of minterms){ let outputString = (minterm+" "); //Count the bits let count = 0; for (var i = maxNumBits; i >= 0; --i) { if((minterm >> i) & 1){ ++count; outputString += "1"; }else{ outputString += "0"; } } bitGroups[count].push(outputString); } document.body.textContent = ""; document.body.style.setProperty("white-space", "pre"); for(const group of bitGroups){ for(const outputString of group){ document.body.textContent += outputString + "\r\n"; } }
0 likes • 1 view
const permutations = arr => { if (arr.length <= 2) return arr.length === 2 ? [arr, [arr[1], arr[0]]] : arr; return arr.reduce( (acc, item, i) => acc.concat( permutations([...arr.slice(0, i), ...arr.slice(i + 1)]).map(val => [ item, ...val, ]) ), [] ); }; permutations([1, 33, 5]); // [ [1, 33, 5], [1, 5, 33], [33, 1, 5], [33, 5, 1], [5, 1, 33], [5, 33, 1] ]
const toFixed = (n, fixed) => ~~(Math.pow(10, fixed) * n) / Math.pow(10, fixed); // Examples toFixed(25.198726354, 1); // 25.1 toFixed(25.198726354, 2); // 25.19 toFixed(25.198726354, 3); // 25.198 toFixed(25.198726354, 4); // 25.1987 toFixed(25.198726354, 5); // 25.19872 toFixed(25.198726354, 6); // 25.198726
const bucketSort = (arr, size = 5) => { const min = Math.min(...arr); const max = Math.max(...arr); const buckets = Array.from( { length: Math.floor((max - min) / size) + 1 }, () => [] ); arr.forEach(val => { buckets[Math.floor((val - min) / size)].push(val); }); return buckets.reduce((acc, b) => [...acc, ...b.sort((a, b) => a - b)], []); }; bucketSort([6, 3, 4, 1]); // [1, 3, 4, 6]