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heap sort

Nov 19, 2022CodeCatch
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More JavaScript Posts

QM Helper

Mar 22, 2022LeifMessinger

0 likes • 1 view

//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";
}
}

Generate a random HEX color

Nov 18, 2022AustinLeath

0 likes • 1 view

// Or
const randomColor = () => `#${(~~(Math.random()*(1<<24))).toString(16)}`;
console.log(randomColor);

getURLParameters

Nov 19, 2022CodeCatch

0 likes • 1 view

const getURLParameters = url =>
(url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(
(a, v) => (
(a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a
),
{}
);

K-means clustering

Nov 19, 2022CodeCatch

0 likes • 0 views

const kMeans = (data, k = 1) => {
const centroids = data.slice(0, k);
const distances = Array.from({ length: data.length }, () =>
Array.from({ length: k }, () => 0)
);
const classes = Array.from({ length: data.length }, () => -1);
let itr = true;
while (itr) {
itr = false;
for (let d in data) {
for (let c = 0; c < k; c++) {
distances[d][c] = Math.hypot(
...Object.keys(data[0]).map(key => data[d][key] - centroids[c][key])
);
}
const m = distances[d].indexOf(Math.min(...distances[d]));
if (classes[d] !== m) itr = true;
classes[d] = m;
}
for (let c = 0; c < k; c++) {
centroids[c] = Array.from({ length: data[0].length }, () => 0);
const size = data.reduce((acc, _, d) => {
if (classes[d] === c) {
acc++;
for (let i in data[0]) centroids[c][i] += data[d][i];
}
return acc;
}, 0);
for (let i in data[0]) {
centroids[c][i] = parseFloat(Number(centroids[c][i] / size).toFixed(2));
}
}
}
return classes;
};
kMeans([[0, 0], [0, 1], [1, 3], [2, 0]], 2); // [0, 1, 1, 0]

ESPN Web Scrape

Oct 15, 2023LeifMessinger

0 likes • 6 views

//Disclaimer: I do not condone mass web scraping of ESPN websites, and this is just theoretical code that hasn't been used.
//Scrape player stats off of https://www.espn.com/nfl/team/roster/_/name/phi/philadelphia-eagles
//Example player JS object
/*
{
"shortName": "S. Opeta",
"name": "Sua Opeta",
"href": "http://www.espn.com/nfl/player/_/id/3121009/sua-opeta",
"uid": "s:20~l:28~a:3121009",
"guid": "dec19157-e984-f981-3724-498281328c97",
"id": "3121009",
"height": "6' 4\"",
"weight": "305 lbs",
"age": 27,
"position": "G",
"jersey": "78",
"birthDate": "08/15/96",
"headshot": "https://a.espncdn.com/i/headshots/nfl/players/full/3121009.png",
"lastName": "Sua Opeta",
"experience": 4,
"college": "Weber State"
}
*/
//The page needs to be focused, so you have to put this code in a bookmarklet and click the page before clicking it. Allegedly.
navigator.clipboard.writeText(JSON.stringify(
window["__espnfitt__"].page.content.roster.groups.flatMap((group)=>{
return group.athletes.map((athlete)=>{
//We can assume all football players are above 100 lbs and below 1000 lbs.
athlete.weight = parseInt(athlete.weight.substring(0,3));
if(athlete.experience == "R") athlete.experience = 0;
else athlete.experience = parseInt(athlete.experience);
//We can assume players are at least 1 foot, or under 10 feet tall.
athlete.inches = 12 * parseInt(athlete.height.substring(0, 1)); //Add feet in inches
athlete.inches += parseInt(athlete.height.substring(2).replaceAll("\"", "").trim()); //Add remaining inches
const monthDayYear = athlete.birthDate.split("/");
athlete.birthMonth = parseInt(monthDayYear[0]);
athlete.birthDay = parseInt(monthDayYear[1]);
athlete.birthYear = parseInt(monthDayYear[2]);
//The only really useful stuff we get from this is Height, weight, left handedness, age, position, and birthday
return athlete;
});
})
, null, "\t")).then(null, ()=>{alert("That failed.")});
//Changes all the team links on this page https://www.espn.com/nfl/stats/team to the team's roster for easier scraping
$$("table > tbody > tr > td > div > div > a").forEach((elm)=>{
elm.setAttribute("href", elm.getAttribute("href").replace("team/", "team/roster/"));
});

power set

Nov 19, 2022CodeCatch

0 likes • 2 views

const powerset = arr =>
arr.reduce((a, v) => a.concat(a.map(r => r.concat(v))), [[]]);
powerset([1, 2]); // [[], [1], [2], [1, 2]]