//------------------------------------------------------------------

float function_IterativeSquareRoot (float x) {

  // http://en.wikipedia.org/wiki/Methods_of_computing_square_roots

  // Ancient Babylonian technology

  functionName = "Iterative (Heron's) Square Root";

  float y = 0.5; 

  int n = 6;

  for (int i=0; i<n; i++) {

    y = (y + x/y)/2.0;

  }

  return y;

}

// by Arnauld - https://codegolf.stackexchange.com/users/58563/arnauld

f=(n,a=b=1,p)=>n?''.padEnd(p)+a+`+${b}=${b+=a}

`+f(n-1,b-a,(a+"").length-~p):''

console.log(f(20))

const stepBetweenA = (min, max, steps) => 

  Array(steps).fill(0).reduce((prev, curr, i) => {

    prev.push(min + ((max - min) / (steps - 1)) * i)

    return prev

  }, [])

const stepBetweenB = (min, max, steps) => {

  steps -= 1

  const diff = (max - min) / steps

  const result = [min]

  for (let i = 0; i < steps; i++) {

    result.push(min += diff)

  }

  return result

}

console.log('a', stepBetweenA(10, 110, 4))

console.log('b', stepBetweenB(10, 110, 4))

const ITER = 10000

console.time('a')

for (let i = 0; i < ITER; i++) {

  stepBetweenA(10, 110, 4)

}

console.timeEnd('a')

  console.time('b')

for (let i = 0; i < ITER; i++) {

  stepBetweenB(10, 110, 4)

}

console.timeEnd('b')

function hamming(a, b) {

  const leng = a.length

  let dist = 0

  // strings need to be same length

  if (leng != b.length) return -1;

  a = a.toLowerCase()

  b = b.toLowerCase()

  for (let i = 0; i < leng; i++)

    if (a[i] !== b[i]) dist++

  return dist

}

console.log(hamming('zevan', 'kevin'))

console.log(hamming('joe', 'joe'))

console.log(hamming('john', 'jake'))

let anchors

let idx

let leng = 10

let size = 200

let px = 0

let py = 0

function seed() {

  idx = 0

  anchors = (Date.now() + '').split``

    .reverse()

    .map(v => parseFloat(v) / 10)

    .splice(0, leng)

}

let last = 0

let zoom = 1

function rand() {

  if (idx > size * size) seed()

  px += zoom

  py += ~~(px / size)

  if (px >= size) px = 0

  if (py >= size) py = 0

  const point = {

    x: anchors[idx % leng],

    y: anchors[(idx + 1) % leng]

  }

  idx++

  let dists = []

  for (let i = 0; i < anchors.length; i += 2) {

    let dx = px - anchors[i] * size

    let dy = py - anchors[i + 1] * size

    dists.push(Math.sqrt(dx * dx + dy * dy))

  }

  dists.sort()

  last += (dists[0] / size - last) / 4

  return last

}

seed()

let d = document

let b = d.body

with (b.appendChild(

  Object.assign(d.createElement`canvas`, { width: 400, height: 400 })

).getContext`2d`) {

  fillStyle = 'black'

  fillRect(0, 0, 400, 400)

  for (let i = 0; i < 200; i++) {

    for (let j = 0; j < 200; j++) {

      const c = rand() * 255

      fillStyle = `rgb(${c}, ${c}, ${c})`

      fillRect(j * 2, i * 2, 1, 2)

    }

  }

}