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Problem 52: Permuted multiples

curriculum/challenges/english/blocks/project-euler-problems-1-to-100/5900f3a01000cf542c50feb3.md

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--description--

It can be seen that the number, 125874, and its double, 251748, contain exactly the same digits, but in a different order.

Find the smallest positive integer, such that multiplied by integers $\{2, 3, \ldots, n\}$, contain the same digits.

--hints--

permutedMultiples(2) should return a number.

js
assert(typeof permutedMultiples(2) === 'number');

permutedMultiples(2) should return 125874.

js
assert.strictEqual(permutedMultiples(2), 125874);

permutedMultiples(6) should return 142857.

js
assert.strictEqual(permutedMultiples(6), 142857);

--seed--

--seed-contents--

js
function permutedMultiples(n) {

  return true;
}

permutedMultiples(2);

--solutions--

js
function permutedMultiples(n) {
    const isPermutation = (a, b) =>
        a.length !== b.length
            ? false
            : a.split('').sort().join() === b.split('').sort().join();


    let start = 1;
    let found = false;
    let result = 0;

    while (!found) {
        start *= 10;
        for (let i = start; i < start * 10 / n; i++) {
            found = true;
            for (let j = 2; j <= n; j++) {
                if (!isPermutation(i + '', j * i + '')) {
                    found = false;
                    break;
                }
            }
            if (found) {
                result = i;
                break;
            }
        }
    }

    return result;
}