From 528bdd7ccdcd0a089f30f34e41c1885e2bea217d Mon Sep 17 00:00:00 2001 From: Rohit Tanwar Date: Fri, 22 Dec 2017 16:58:16 +0530 Subject: [PATCH] add snippet fibonacciTillNum --- snippets/fibonacciTillNum.md | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 snippets/fibonacciTillNum.md diff --git a/snippets/fibonacciTillNum.md b/snippets/fibonacciTillNum.md new file mode 100644 index 000000000..252000907 --- /dev/null +++ b/snippets/fibonacciTillNum.md @@ -0,0 +1,14 @@ +### fibonaciiTillNum + +Generates an array, containing the Fibonacci sequence, up until the nth term. + +Create an empty array of the specific length, initializing the first two values (`0` and `1`). +Use `Array.reduce()` to add values into the array, using the sum of the last two values, except for the first two. +Uses a mathematical formula to calculate the length of the array required +```js +const fibonacciTillNum = num => { + let n = Math.ceil(Math.log(num * Math.sqrt(5) + 1/2) / Math.log((Math.sqrt(5)+1)/2))// fibonacci(5) -> [0,1,1,2,3]; + return Array.from({ length: n}).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), []); + } + \\ fibsTillNum(15) -> [0,1,1,2,3,5,8,13] +``` \ No newline at end of file