6cfd0fc503
* fix: improve Project Euler descriptions and test case Improve formatting of Project Euler test descriptions. Also add poker hands array and new test case for problem 54 * feat: add typeof tests and gave functions proper names for first 100 challenges * fix: continue fixing test descriptions and adding "before test" sections * fix: address review comments * fix: adjust grids in 18 and 67 and fix some text that reference files rather than the given arrays * fix: implement bug fixes and improvements from review * fix: remove console.log statements from seed and solution
94 lines
1.7 KiB
Markdown
94 lines
1.7 KiB
Markdown
---
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id: 5900f3a01000cf542c50feb3
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challengeType: 5
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title: 'Problem 52: Permuted multiples'
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forumTopicId: 302163
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---
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## Description
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<section id='description'>
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It can be seen that the number, 125874, and its double, 251748, contain exactly the same digits, but in a different order.
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Find the smallest positive integer, <var>x</var>, such that <var>2x</var>, <var>3x</var>, <var>4x</var>, <var>5x</var>, and <var>6x</var>, contain the same digits.
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>permutedMultiples()</code> should return a number.
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testString: assert(typeof permutedMultiples() === 'number');
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- text: <code>permutedMultiples()</code> should return 142857.
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testString: assert.strictEqual(permutedMultiples(), 142857);
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function permutedMultiples() {
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// Good luck!
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return true;
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}
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permutedMultiples();
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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function permutedMultiples() {
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const isPermutation = (a, b) =>
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a.length !== b.length
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? false
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: a.split('').sort().join() === b.split('').sort().join();
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let start = 1;
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let found = false;
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let result = 0;
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while (!found) {
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start *= 10;
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for (let i = start; i < start * 10 / 6; i++) {
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found = true;
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for (let j = 2; j <= 6; j++) {
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if (!isPermutation(i + '', j * i + '')) {
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found = false;
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break;
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}
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}
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if (found) {
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result = i;
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break;
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}
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}
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}
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return result;
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}
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```
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</section>
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