Compute inverse-depth weighted sum of nested lists

Q: Compute inverse-depth weighted sum of nested lists

This question evaluates understanding of nested list traversal, depth computation, and weighted aggregation by the inverse of depth, focusing on concepts like maximum depth calculation and applying weights across hierarchical integer elements.

Q: How do I approach Coding & Algorithms interview questions?

Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

Question

Inverse-Depth Weighted Sum of a Nested List

You are given a nested list of integers. Each element is either:

an integer, or
another nested list.

Define the depth of an integer as the number of lists it is inside (top-level integers have depth 1).

Compute the inverse-depth weighted sum:

Let D be the maximum depth in the structure.
An integer at depth d has weight D - d + 1 .
Return the sum of value * weight over all integers.

Input

A nested list structure (you may assume an interface like:
- isInteger() , getInteger() , getList() ), or an equivalent representation.

Output

An integer: the inverse-depth weighted sum.

Example

Input: [1, [4, [6]]]

Depths: 1 at depth 1, 4 at depth 2, 6 at depth 3. Max depth D=3 .
Weights: depth1 -> 3, depth2 -> 2, depth3 -> 1
Sum = 1*3 + 4*2 + 6*1 = 17

Constraints

Total number of integers across all lists can be up to e.g. 10^4 .
Integers fit in 32-bit signed range.