From 6ddf62ec04e84f29f23074bce36f60c8f5bc9bf6 Mon Sep 17 00:00:00 2001 From: Angelos Chalaris Date: Tue, 13 Oct 2020 10:17:21 +0300 Subject: [PATCH] Update isSorted.md --- snippets/isSorted.md | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/snippets/isSorted.md b/snippets/isSorted.md index 7ec0b417e..347e998df 100644 --- a/snippets/isSorted.md +++ b/snippets/isSorted.md @@ -3,17 +3,18 @@ title: isSorted tags: array,intermediate --- -Returns `1` if an array of numbers is sorted in ascending order, `-1` if it is sorted in descending order or `0` if it is not sorted. +Returns `1` if a numeric array is sorted in ascending order, `-1` if it is sorted in descending order or `0` if it is not sorted. -- Calculate the ordering `direction` for every pair of adjacent array elements. -- Return `0` if the `direction` changes or the `direction` sign if the last element is reached. +- Calculate the ordering `direction` for the first pair of adjacent array elements. +- Return `0` if the given array is empty, only has one element or the `direction` changes for any pair of adjacent array elements. +- Use `Math.sign()` to covert the final value of `direction` to `-1` or `1`. ```js const isSorted = arr => { - let direction = 0; - for (let i = 1; i < arr.length; i++) { - if (!direction) direction = arr[i] - arr[i - 1]; - else if ((arr[i] - arr[i - 1]) * direction < 0) return 0; + if (arr.length <= 1) return 0; + const direction = arr[1] - arr[0]; + for (let i = 2; i < arr.length; i++) { + if ((arr[i] - arr[i - 1]) * direction < 0) return 0; } return Math.sign(direction); };