19 lines
678 B
Markdown
19 lines
678 B
Markdown
### fibonacciUntilNum
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Generates an array, containing the Fibonacci sequence, up until the nth term.
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Create an empty array of the specific length, initializing the first two values (`0` and `1`).
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Use `Array.reduce()` to add values into the array, using the sum of the last two values, except for the first two.
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Uses a mathematical formula to calculate the length of the array required.
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```js
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const fibonacciUntilNum = num => {
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let n = Math.ceil(Math.log(num * Math.sqrt(5) + 1/2) / Math.log((Math.sqrt(5)+1)/2));
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return Array.from({ length: n}).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), []);
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}
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```
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```js
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fibonacciCountUntilNum(10) -> 7
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```
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