61 lines
1.3 KiB
Markdown
61 lines
1.3 KiB
Markdown
---
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id: 5900f4841000cf542c50ff97
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challengeType: 5
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title: 'Problem 280: Ant and seeds'
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---
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## Description
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<section id='description'>
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A laborious ant walks randomly on a 5x5 grid. The walk starts from the central square. At each step, the ant moves to an adjacent square at random, without leaving the grid; thus there are 2, 3 or 4 possible moves at each step depending on the ant's position.
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At the start of the walk, a seed is placed on each square of the lower row. When the ant isn't carrying a seed and reaches a square of the lower row containing a seed, it will start to carry the seed. The ant will drop the seed on the first empty square of the upper row it eventually reaches.
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What's the expected number of steps until all seeds have been dropped in the top row?
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Give your answer rounded to 6 decimal places.
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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>euler280()</code> should return 430.088247.
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testString: assert.strictEqual(euler280(), 430.088247, '<code>euler280()</code> should return 430.088247.');
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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 euler280() {
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// Good luck!
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return true;
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}
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euler280();
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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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