amejiarosario

tmux shortcuts & cheatsheet v1.1.0

start new:

tmux

start new with session name:

tmux new -s myname

amejiarosario

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

amejiarosario

time node ./lib/permutations.js
# getPermutations('abcdefghij') // => abcdefghij, abcdefghji, abcdefgihj, abcdefgijh, abcdefgjhi, abcdefgjih, abcdefhgij...
# // n = 10, f(n) = 3,628,800;
# ./lib/permutations.js  8.06s user 0.63s system 101% cpu 8.562 total

amejiarosario

getPermutations('ab') // ab, ba...
// n = 2, f(n) = 2;
getPermutations('abc') // abc, acb, bac, bca, cab, cba...
// n = 3, f(n) = 6;
getPermutations('abcd') // abcd, abdc, acbd, acdb, adbc, adcb, bacd...
// n = 4, f(n) = 24;
getPermutations('abcde') // abcde, abced, abdce, abdec, abecd, abedc, acbde...
// n = 5, f(n) = 120;

amejiarosario

function getPermutations(string, prefix = '') {
  if(string.length <= 1) {
    return [prefix + string];
  }

  return Array.from(string).reduce((result, char, index) => {
    const reminder = string.slice(0, index) + string.slice(index+1);
    result = result.concat(getPermutations(reminder, prefix + char));
    return result;
  }, []);

amejiarosario

getPermutations('a') // => [ 'a']
getPermutations('ab') // =>  [ 'ab', 'ba']
getPermutations('abc') // => [ 'abc', 'acb', 'bac', 'bca', 'cab', 'cba' ]

amejiarosario

powerset('') // ...
// n = 0, f(n) = 1;
powerset('a') // , a...
// n = 1, f(n) = 2;
powerset('ab') // , a, b, ab...
// n = 2, f(n) = 4;
powerset('abc') // , a, b, ab, c, ac, bc, abc...
// n = 3, f(n) = 8;
powerset('abcd') // , a, b, ab, c, ac, bc, abc, d, ad, bd, abd, cd, acd, bcd...
// n = 4, f(n) = 16;

amejiarosario

function powerset(n = '') {
  const array = Array.from(n);
  const base = [''];

  const results = array.reduce((previous, element) => {
    const previousPlusElement = previous.map(el => {
      return `${el}${element}`;
    });
    return previous.concat(previousPlusElement);
  }, base);

amejiarosario

function hasDuplicates(n) {
  const duplicates = [];
  let counter = 0; // debug

  for (let outter = 0; outter < n.length; outter++) {
    for (let inner = 0; inner < n.length; inner++) {
      counter++; // debug

      if(outter === inner) continue;

amejiarosario

powerset('') // =>  ['']
powerset('a') // => ['', 'a']
powerset('ab') // => ['', 'a', 'b', 'ab']