bjkeller

var SimpleHashTable = function(hashCode) {
  var table = [];
  var Constructor = function() { };
  Constructor.prototype.add = function(opts) {

  };
  return new Constructor();
}

module.exports.SimpleHashTable = SimpleHashTable;

rochoa

Check the conversation here https://twitter.com/felipernb/status/499661739244281859

As Felipe mentions native sort covers many edge cases so native method is less performant. However I get totally different results using node.js in different versions, check results_node_* files.

Some edge cases, see tests.js file:

• Sorting [1, null] produces different result in native than in algorithms.js.
• ['a', null, 'a'] produces inconsistent results in algorithms.js.

kevincennis

var EventEmitter = (function() {

  var cache = new WeakMap();

  function EventEmitter() {
    cache.set( this, {} );
  }

  EventEmitter.prototype = {
    

tjunghans

Frontend Developer Interview Questions

JavaScript

Types

• What are the primitive/native types exist?
• Which built-in prototypes exist?
• What is the difference between a primitive and complex type?
• Which primitives have corresponding objects?

rain1024

Graph Search Algorithm

Shortest Path Problem ^[1]

Algorithms

• Dijkstra's algorithm solves the single-source shortest path problem.
• Bellman–Ford algorithm solves the single-source problem if edge weights may be negative.
• A* search algorithm solves for single pair shortest path using heuristics to try to speed up the search.
• Floyd–Warshall algorithm solves all pairs shortest paths.

egrueter-dev

ALGORITHMS AND INTERVIEW QUESTIONS CHEAT SHEET

DATA STRUCTURES

A data structure is a group of data organized in the computer's memory by certain specific rules defining predictable relationships between the data. Arrays, hashes and relational databases are all examples of data structures.

eriksjaastad

###Time Complexity O(1) is constant time, no matter how much data there is, it will take the same amount of time to find the answer
O(log n) is cutting the search area in half each time
O(n) is looping through each item once
O(n²) is looping through twice
0(nⁿ) is looping through each value and having to do something with each value based on how many values came before it
####TapeEquilibrium rewrite
A is an Array = [3,1,2,4,3]
N is the length of A

GoSteven

Ant colony algorithm

Thus, when one ant finds a good (i.e., short) path from the colony to a food source, other ants are more likely to follow that path, and positive feedback eventually leads all the ants following a single path. The idea of the ant colony algorithm is to mimic this behavior with "simulated ants" walking around the graph representing the problem to solve.

---

List of algorithms

riovv

/*
 * Count inversions in an array using JavaScript
 * Friday fun writing algorithms as UNREADABLE CODE WITH FEW LINEZ FTW :D::D
 */

var array_inversions = function (A) {
  var I = 0, 
      R = function (A) { return (A.length < 2) ? A : M(R(A.splice(0, A.length/2)), R(A)) },
      M = function (B, C) {
        var D = []    

magic003

• Consider using HashMap when comparing two strings or arrays.
• When handling string problems, ask if it is ASCII. Use an array of length 256 if it is.
• When comparing two strings or arrays, sort them first.
• Using StringBuffer for the temporary result for string concatenate.
• Prepend a dummy node for linked list problems.
• Remember integer might be negative!
• Computer cannot accurately represent float/double, use epsilon for equality check.

Common tricks:

• Interval intersection: 1) sort by start point, binary search the end point 2) sort both start and end points, go through the array, for start point i++, for end point i--.