26 lines
635 B
Markdown
26 lines
635 B
Markdown
---
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title: Greatest common divisor
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tags: math,algorithm,recursion
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cover: blog_images/flower-pond.jpg
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firstSeen: 2017-12-17T17:55:51+02:00
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lastUpdated: 2020-12-29T12:36:50+02:00
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---
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Calculates the greatest common divisor between two or more numbers/arrays.
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- The inner `_gcd` function uses recursion.
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- Base case is when `y` equals `0`. In this case, return `x`.
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- Otherwise, return the GCD of `y` and the remainder of the division `x / y`.
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```js
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const gcd = (...arr) => {
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const _gcd = (x, y) => (!y ? x : gcd(y, x % y));
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return [...arr].reduce((a, b) => _gcd(a, b));
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};
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```
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```js
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gcd(8, 36); // 4
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gcd(...[12, 8, 32]); // 4
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```
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