59 lines
1.3 KiB
Markdown
59 lines
1.3 KiB
Markdown
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---
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id: 5900f5101000cf542c510022
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title: 'Problem 419: Look and say sequence'
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challengeType: 5
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forumTopicId: 302088
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dashedName: problem-419-look-and-say-sequence
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---
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# --description--
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The look and say sequence goes 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...
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The sequence starts with 1 and all other members are obtained by describing the previous member in terms of consecutive digits.
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It helps to do this out loud:
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1 is 'one one' → 11
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11 is 'two ones' → 21
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21 is 'one two and one one' → 1211
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1211 is 'one one, one two and two ones' → 111221
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111221 is 'three ones, two twos and one one' → 312211
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...
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Define A(n), B(n) and C(n) as the number of ones, twos and threes in the n'th element of the sequence respectively. One can verify that A(40) = 31254, B(40) = 20259 and C(40) = 11625.
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Find A(n), B(n) and C(n) for n = 1012. Give your answer modulo 230 and separate your values for A, B and C by a comma. E.g. for n = 40 the answer would be 31254,20259,11625
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# --hints--
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`euler419()` should return 998567458, 1046245404, 43363922.
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```js
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assert.strictEqual(euler419(), 998567458, 1046245404, 43363922);
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```
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# --seed--
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## --seed-contents--
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```js
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function euler419() {
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return true;
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}
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euler419();
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```
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# --solutions--
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```js
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// solution required
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```
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