2018-09-30 22:01:58 +00:00
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---
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id: 5900f3e81000cf542c50fefb
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challengeType: 5
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title: 'Problem 124: Ordered radicals'
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---
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## Description
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<section id='description'>
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The radical of n, rad(n), is the product of the distinct prime factors of n. For example, 504 = 23 × 32 × 7, so rad(504) = 2 × 3 × 7 = 42.
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If we calculate rad(n) for 1 ≤ n ≤ 10, then sort them on rad(n), and sorting on n if the radical values are equal, we get:
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Unsorted
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Sorted
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n
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rad(n)
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n
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rad(n)
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k
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11
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111
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22
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222
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33
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423
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42
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824
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55
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335
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66
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936
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77
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557
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82
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668
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93
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779
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1010
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101010
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Let E(k) be the kth element in the sorted n column; for example, E(4) = 8 and E(6) = 9.
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If rad(n) is sorted for 1 ≤ n ≤ 100000, find E(10000).
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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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2018-10-04 13:37:37 +00:00
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tests:
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- text: <code>euler124()</code> should return 21417.
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2018-10-20 18:02:47 +00:00
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testString: assert.strictEqual(euler124(), 21417, '<code>euler124()</code> should return 21417.');
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2018-09-30 22:01:58 +00:00
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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 euler124() {
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// Good luck!
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return true;
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}
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euler124();
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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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// solution required
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```
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</section>
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