66 lines
1.4 KiB
Markdown
66 lines
1.4 KiB
Markdown
---
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id: 5900f3911000cf542c50fea4
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challengeType: 5
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title: 'Problem 37: Truncatable primes'
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forumTopicId: 302031
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---
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## Description
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<section id='description'>
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The number 3797 has an interesting property. Being prime itself, it is possible to continuously remove digits from left to right, and remain prime at each stage: 3797, 797, 97, and 7. Similarly we can work from right to left: 3797, 379, 37, and 3.
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Find the sum of the only n (8 <= n <= 11) primes that are both truncatable from left to right and right to left.
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NOTE: 2, 3, 5, and 7 are not considered to be truncatable primes.
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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>truncatablePrimes(8)</code> should return 1986.
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testString: assert(truncatablePrimes(8) == 1986);
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- text: <code>truncatablePrimes(9)</code> should return 5123.
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testString: assert(truncatablePrimes(9) == 5123);
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- text: <code>truncatablePrimes(10)</code> should return 8920.
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testString: assert(truncatablePrimes(10) == 8920);
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- text: <code>truncatablePrimes(11)</code> should return 748317.
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testString: assert(truncatablePrimes(11) == 748317);
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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 truncatablePrimes(n) {
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// Good luck!
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return n;
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}
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truncatablePrimes(11);
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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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