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🔥Flatten Multi-Dimensional Array (DOM & AST Engine)Easy
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EasyWeb Engineering•Acceptance: 72.4%

Flatten Multi-Dimensional Array (DOM & AST Engine)

Targeted in FAANG & Tech OA:GoogleAmazonMicrosoftSwiggyUber
Real-World Engineering Context
Used in React virtual DOM reconciliation, AST compilers (Babel), and CSS-in-JS rule unrolling.
Given a deeply nested multi-dimensional array with arbitrary nesting depth, return a flattened 1-dimensional array preserving original element order without using native `.flat(Infinity)`.

Sample Test Cases

Input: [[1,[2,[3,[4]],5]]]
Expected: [1,2,3,4,5]
Input: [[[1,2],[3,4],[5]]]
Expected: [1,2,3,4,5]

Constraints

  • 0 <= arr.length <= 10^4
  • Total nested elements <= 10^5
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