Skip to content

Instantly share code, notes, and snippets.

Peter Hayes peterkhayes

Block or report user

Report or block peterkhayes

Hide content and notifications from this user.

Learn more about blocking users

Contact Support about this user’s behavior.

Learn more about reporting abuse

Report abuse
View GitHub Profile
peterkhayes / disjointSet.js
Created May 3, 2017
Javascript Disjoint Set
View disjointSet.js
Useful for HackerRank problems.
function main (numNodes, edges) {
const parent = [];
const rank = [];
function makeSet (x) {
peterkhayes / gist:fcb7548ef7cde329c460
Last active May 6, 2016
Lecture notes for Intermediate Data Structures talk
View gist:fcb7548ef7cde329c460
I) About me:
a) Peter Hayes, engineer at ClassDojo
b) Studied mathematical economics at Brown, used to be a high school math teacher
c) Follow me on github/check out my npm. don't follow my twitter
II) Introduction
a) Topics today: heaps, quadtrees, graphs
b) What are data structures for?
1) Not just to store data - an unstructured blob can store data
3) Rather: store data with *efficient* insertion, access, and retrieval
View gist:2276e305ff74cce8131e
On schoolTeacher resource:
_items: [
_id: 1234
_links: {
befriend/poolWith/etc: {
href: "/api/teacher/1234/friends",
method: "POST",
peterkhayes / Description
Created May 20, 2014
Making-Change problem with Dynamic Programming
View Description
// We write the problem as a table. Each row represents the amount of change to make,
// and the value at each column represents the highest coin we're allowed to use
// in making that amount of change
// That is to say, in row 5, col 2 is the number of ways to make 5 cents, using only the two lowest coins.
// To calculate the value of each square, we add the values of two other squares together -
// * The square to the left, which represents all possibilites using smaller coins.
// * The square as many rows above as the value of that coin.
// This is all possibilities after taking away one of this coin
// This method avoids having to ever call things recursively - we just build a big table!
peterkhayes / montecarlo.js
Last active Aug 29, 2015
monte carlo solution
View montecarlo.js
var integrate = function() {
// return 42;
var iters = 2000;
var d = getGraphDimensions();
var width = d.x.max - d.x.min;
var height = d.y.max - d.y.min;
var xmin = d.x.min;
You can’t perform that action at this time.