88 lines
1.8 KiB
Markdown
88 lines
1.8 KiB
Markdown
---
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id: 595668ca4cfe1af2fb9818d4
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title: Harshad or Niven series
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challengeType: 5
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forumTopicId: 302281
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dashedName: harshad-or-niven-series
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---
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# --description--
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The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
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For example, `42` is a Harshad number as `42` is divisible by `(4 + 2)` without remainder.
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Assume that the series is defined as the numbers in increasing order.
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# --instructions--
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Implement a function to generate successive members of the Harshad sequence.
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Use it to return an array with ten members of the sequence, starting with first Harshad number greater than `n`.
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# --hints--
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`isHarshadOrNiven` should be a function.
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```js
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assert(typeof isHarshadOrNiven === 'function');
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```
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`isHarshadOrNiven(10)` should return `[12, 18, 20, 21, 24, 27, 30, 36, 40, 42]`
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```js
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assert.deepEqual(isHarshadOrNiven(10), [12, 18, 20, 21, 24, 27, 30, 36, 40, 42]);
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```
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`isHarshadOrNiven(400)` should return `[402, 405, 407, 408, 410, 414, 420, 423, 432, 440]`
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```js
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assert.deepEqual(isHarshadOrNiven(400), [402, 405, 407, 408, 410, 414, 420, 423, 432, 440]);
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```
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`isHarshadOrNiven(1000)` should return `[1002, 1008, 1010, 1011, 1012, 1014, 1015, 1016, 1017, 1020]`
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```js
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assert.deepEqual(isHarshadOrNiven(1000), [1002, 1008, 1010, 1011, 1012, 1014, 1015, 1016, 1017, 1020]);
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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 isHarshadOrNiven(n) {
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const res = [];
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return res;
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}
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```
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# --solutions--
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```js
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function isHarshadOrNiven(n) {
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function isHarshad(num) {
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let s = 0;
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const nStr = num.toString();
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for (let i = 0; i < nStr.length; ++i) {
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s += parseInt(nStr.charAt(i), 10);
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}
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return n % s === 0;
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}
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const res = [];
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let count = 0;
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while (count < 10) {
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n++;
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if (isHarshad(n)) {
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count++;
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res.push(n);
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}
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}
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return res;
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}
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```
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