railsstudent

// http://stackoverflow.com/questions/5131497/find-the-index-of-a-given-permutation-in-the-sorted-list-of-the-permutations-of
// http://stackoverflow.com/questions/18644470/anagram-index-calculation/18646156#18646156
var f = [];
function factorial (n) {
  if (n == 0 || n == 1)
    return 1;
  if (f[n] > 0)
    return f[n];
  return f[n] = factorial(n-1) * n;
} 

railsstudent

// http://www.geeksforgeeks.org/find-last-digit-of-ab-for-large-numbers/
//http://qa.geeksforgeeks.org/1061/given-big-number-form-string-how-do-take-mod-of-that-big-number

var asciiZero = "0".charCodeAt(0);
var findModulo = function(base, exponent) {
  var mod = 0;
  for (var i in exponent) {
    //mod = (mod*10 + b[i] - '0')%a;
    mod = (mod * 10 + exponent.charCodeAt(i) - asciiZero) % base;
  }

railsstudent

function handleAcromyn(accumulator, path, isLast) {
  var excluded = ["the","of","in","from","by","with","and", "or", "for", "to", "at", "a"];
  var acromynList = path.split('-');
  var shortener = '';
  for (var k in acromynList) {
    var term = acromynList[k];        
    if (excluded.indexOf(term) < 0) {
      shortener += term[0];
    }
  }

railsstudent

// https://codemyroad.wordpress.com/2014/05/01/solving-sudoku-by-backtracking/
/*
  On the other hand, the backtracking algorithm fills up a blank cell with a 
  valid number (i.e. no two same numbers in any row, column or big box),
  moves on to the next cell, and then does the same thing. If all the possible 
  numbers from 1 to 9 are invalid for any cell that the algorithm is currently “at”, 
  the algorithm moves back to the previous cell and changes that cell’s value to another valid number. Afterwards, it moves back to the next cell and the whole process repeats.
*/
// https://en.wikipedia.org/wiki/Sudoku_solving_algorithms
// use backtracking algorithm

railsstudent

var Sudoku = function(data) 
{
  //   Private methods
  // -------------------------
  var N = data.length;
  var rootN = Math.floor(Math.sqrt(N));
  
  var isValidSubSudoku = function(leftX, leftY, size) {
    var sudokuTracker = {};
    for (var j = leftX; j < leftX+size; j++) {

railsstudent

// http:// stackoverflow.com/questions/23202489/how-does-this-code-find-the-number-of-trailing-zeros-from-any-base-number-factor
// https://comeoncodeon.wordpress.com/2010/02/17/number-of-zeores-and-digits-in-n-factorial-in-base-b/
function zeroes (base, number) {
  
  var noz = Number.MAX_VALUE;
  // Now we can break the Base B as a product of primes :
  // B = a^p1 * b^p2 * c^p3 * …
  //Then the number of trailing zeroes in N factorial in Base B is given by the formulae
  // min{1/p1(n/a + n/(a*a) + ….), 1/p2(n/b + n/(b*b) + ..), ….}.
  var j = base;

railsstudent

function VigenèreCipher(key, abc) {
  
  this.encode = function (str) {
    var encodeStr = ''
    for (var i in str) {
      var c = str[i];
      var k = key[i % key.length];
      if (abc.indexOf(c) >= 0) { 
        encodeStr += abc[(abc.indexOf(c) + abc.indexOf(k)) % abc.length];
      } else {

railsstudent

class VigenereCipher
  constructor: (@key, @abc) ->
    @dict = {}    
    i = 0
    for x in @abc
      shift = @abc[i..] + @abc[0...i]
      @dict[x] = shift
      i++;
      
  encode: (str) ->  

railsstudent

decodeMorse = function(morseCode){
  var decodeString = '';
  var morseCodeWords = morseCode.split('   ');
  for (var i in morseCodeWords) {
    var morseCodeArray = morseCodeWords[i].split(' ');
    for (var j in morseCodeArray) {
      if (MORSE_CODE[morseCodeArray[j]] !== undefined) {
        decodeString += MORSE_CODE[morseCodeArray[j]];
      }
    }

railsstudent

function isValidCoordinates(coordinates){
  
  var coordinatesReg = /^(-?\d+(\.\d+)?),\s*(-?\d+(\.\d+)?)$/g
  if (!coordinatesReg.test(coordinates)) {
    return false;
  }
  
  var arrCoordinates = coordinates.split(',');
  try {
    var strLat = arrCoordinates[0].trim();