/*
 * This is a JavaScript Scratchpad.
 *
 * Enter some JavaScript, then Right Click or choose from the Execute Menu:
 * 1. Run to evaluate the selected text (Ctrl+R),
 * 2. Inspect to bring up an Object Inspector on the result (Ctrl+I), or,
 * 3. Display to insert the result in a comment after the selection. (Ctrl+L)
 */

g=['g']
r=['r']
y=['y']
c=['c']
b=['b']
p=['p']

g.push(r,y)
r.push(c,b)
y.push(r,c)
c.push(p,b)
p.push(g,y)
b.push(p,g)

const isC = (c) => ([color]) => c === color ? 1 : 0

function s (_arr = [], i = 0) {
  const arr = [..._arr]
  const [c, a, b] = arr[i]
  arr.splice(i, 1)
  arr.splice(i, 0, a, b)
  return arr
}

function count (arr, c) {
  return arr.reduce((acc, [color]) => acc + isC(c)(color), 0)
}

function x (arr = [g], hist = []) {
  if (arr.length === 10) {
    const [r, y] = [count(arr, 'r'), count(arr, 'y')]
    if (r === y && r === 5) {
      return [hist]
    } else {
      return []
    }
  } else {
    return arr.flatMap((_, i) => x(s(arr, i), hist.concat([i]))[0])
  }
}