78 lines
2.0 KiB
Markdown
78 lines
2.0 KiB
Markdown
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---
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id: 5900f36f1000cf542c50fe82
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challengeType: 5
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title: 'Problem 3: Largest prime factor'
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---
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## Description
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<section id='description'>
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The prime factors of 13195 are 5, 7, 13 and 29.
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What is the largest prime factor of the given <code>number</code>?
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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>largestPrimeFactor(2)</code> should return 2.
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testString: 'assert.strictEqual(largestPrimeFactor(2), 2, ''<code>largestPrimeFactor(2)</code> should return 2.'');'
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- text: <code>largestPrimeFactor(3)</code> should return 3.
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testString: 'assert.strictEqual(largestPrimeFactor(3), 3, ''<code>largestPrimeFactor(3)</code> should return 3.'');'
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- text: <code>largestPrimeFactor(5)</code> should return 5.
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testString: 'assert.strictEqual(largestPrimeFactor(5), 5, ''<code>largestPrimeFactor(5)</code> should return 5.'');'
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- text: <code>largestPrimeFactor(7)</code> should return 7.
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testString: 'assert.strictEqual(largestPrimeFactor(7), 7, ''<code>largestPrimeFactor(7)</code> should return 7.'');'
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- text: <code>largestPrimeFactor(13195)</code> should return 29.
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testString: 'assert.strictEqual(largestPrimeFactor(13195), 29, ''<code>largestPrimeFactor(13195)</code> should return 29.'');'
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- text: <code>largestPrimeFactor(600851475143)</code> should return 6857.
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testString: 'assert.strictEqual(largestPrimeFactor(600851475143), 6857, ''<code>largestPrimeFactor(600851475143)</code> should return 6857.'');'
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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 largestPrimeFactor(number) {
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// Good luck!
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return true;
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}
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largestPrimeFactor(13195);
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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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const largestPrimeFactor = (number)=>{
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let largestFactor = number;
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for(let i = 2;i<largestFactor;i++){
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if(!(largestFactor%i)){
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largestFactor = largestFactor/i;
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largestPrimeFactor(largestFactor);
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}
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}
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return largestFactor;
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}
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```
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</section>
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