2018-09-30 22:01:58 +00:00
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---
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id: 5900f4181000cf542c50ff2b
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title: 'Problem 172: Investigating numbers with few repeated digits'
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2020-11-27 18:02:05 +00:00
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challengeType: 5
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2019-08-05 16:17:33 +00:00
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forumTopicId: 301807
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2021-01-13 02:31:00 +00:00
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dashedName: problem-172-investigating-numbers-with-few-repeated-digits
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2018-09-30 22:01:58 +00:00
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---
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2020-11-27 18:02:05 +00:00
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# --description--
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2018-09-30 22:01:58 +00:00
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2021-07-12 14:19:03 +00:00
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How many 18-digit numbers $n$ (without leading zeros) are there such that no digit occurs more than three times in $n$?
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2018-09-30 22:01:58 +00:00
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2020-11-27 18:02:05 +00:00
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# --hints--
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2018-09-30 22:01:58 +00:00
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2021-07-12 14:19:03 +00:00
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`numbersWithRepeatedDigits()` should return `227485267000992000`.
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2018-09-30 22:01:58 +00:00
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2020-11-27 18:02:05 +00:00
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```js
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2021-07-12 14:19:03 +00:00
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assert.strictEqual(numbersWithRepeatedDigits(), 227485267000992000);
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2018-09-30 22:01:58 +00:00
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```
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2020-11-27 18:02:05 +00:00
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# --seed--
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2018-09-30 22:01:58 +00:00
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2020-11-27 18:02:05 +00:00
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## --seed-contents--
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2018-09-30 22:01:58 +00:00
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```js
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2021-07-12 14:19:03 +00:00
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function numbersWithRepeatedDigits() {
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2020-09-15 16:57:40 +00:00
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2018-09-30 22:01:58 +00:00
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return true;
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}
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2021-07-12 14:19:03 +00:00
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numbersWithRepeatedDigits();
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2018-09-30 22:01:58 +00:00
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```
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2020-11-27 18:02:05 +00:00
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# --solutions--
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2018-09-30 22:01:58 +00:00
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```js
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// solution required
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```
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