2635. Apply Transform Over Each Element in Array
Description
Given an integer array arr
and a mapping function fn
, return a new array with a transformation applied to each element.
The returned array should be created such that returnedArray[i] = fn(arr[i], i)
.
Please solve it without the built-in Array.map
method.
Example 1:
Input: arr = [1,2,3], fn = function plusone(n) { return n + 1; } Output: [2,3,4] Explanation: const newArray = map(arr, plusone); // [2,3,4] The function increases each value in the array by one.
Example 2:
Input: arr = [1,2,3], fn = function plusI(n, i) { return n + i; } Output: [1,3,5] Explanation: The function increases each value by the index it resides in.
Example 3:
Input: arr = [10,20,30], fn = function constant() { return 42; } Output: [42,42,42] Explanation: The function always returns 42.
Constraints:
0 <= arr.length <= 1000
-109 <= arr[i] <= 109
fn
returns a number
Solutions
Solution 1: traversal
We traverse the array $arr$, for each element $arr[i]$, replace it with $fn(arr[i], i)$. Finally, return the array $arr$.
The time complexity is $O(n)$, where $n$ is the length of the array $arr$. The space complexity is $O(1)$.
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