60 lines
1.1 KiB
Markdown
60 lines
1.1 KiB
Markdown
---
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id: 5900f3bb1000cf542c50fece
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challengeType: 5
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title: 'Problem 79: Passcode derivation'
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forumTopicId: 302192
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---
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## Description
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<section id='description'>
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A common security method used for online banking is to ask the user for three random characters from a passcode. For example, if the passcode was 531278, they may ask for the 2nd, 3rd, and 5th characters; the expected reply would be: 317.
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The text file, keylog.txt, contains fifty successful login attempts.
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Given that the three characters are always asked for in order, analyse the file so as to determine the shortest possible secret passcode of unknown length.
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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>euler79()</code> should return 73162890.
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testString: assert.strictEqual(euler79(), 73162890);
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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 euler79() {
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// Good luck!
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return true;
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}
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euler79();
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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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