multiples-by-permutations.js

/*
We have two consecutive integers k1 and k2, k2 = k1 + 1

We need to calculate the lowest strictly positive integer n, such that: the values nk1 and nk2 have the same digits but in different order.

E.g.# 1:

k1 = 100
k2 = 101
n = 8919
#Because 8919 * 100 = 891900 
and      8919 * 101 = 900819
E.g.# 2:

k1 = 325
k2 = 326
n = 477
#Because 477 * 325 = 155025
and      477 * 326 = 155502
Your task is to prepare a function that will receive the value of k and outputs the value of n.

The examples given above will be:

find_lowest_int(100) === 8919
find_lowest_int(325) ===  477
Features of the random tests

10 < k < 10.000.000.000.000.000 (For Python, Ruby and Haskell)
10 < k < 1.000.000.000  (For Javascript and D 1e9)
Enjoy it!!
*/

function findLowestInt(k) {
    // your code here
    var lowestInt;
    let k2 = k + 1
    
  for (let lowestInt = 1; lowestInt < 1000000001; lowestInt++){
    let nk1 = k  * lowestInt
    let nk2 = k2 * lowestInt
    nk1 = nk1.toString().split('').sort().join('')
    nk2 = nk2.toString().split('').sort().join('')
    if (nk1 == nk2) return lowestInt
  }
}