Polyfill for Flattening Arrays | Dataford Interview Questions

Write a polyfill for flattening out an array.

Implement flatten_array(arr), which accepts a list containing values or nested lists and returns a new one-dimensional list with all nesting removed. Preserve left-to-right order, retain duplicate values, and do not mutate arr. For example, [1, [2, [3]], 4] becomes [1, 2, 3, 4], while [] becomes [].

Constraints

0 <= number of top-level elements <= 10^4
The total number of values and nested lists is at most 10^4
Nesting depth is at most 10^3
Each non-list value may be any Python value
The input list must not be mutated

Function Signature

def flatten_array(arr):

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Problem

Write a polyfill for flattening out an array.

Constraints

0 <= number of top-level elements <= 10^4
The total number of values and nested lists is at most 10^4
Nesting depth is at most 10^3
Each non-list value may be any Python value
The input list must not be mutated

Function Signature

def flatten_array(arr):

Your question is Polyfill for Flattening Arrays. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.