Return the k-th row of Pascal-like triangle

Q: Return the k-th row of Pascal-like triangle

This question evaluates combinatorics, array manipulation, and space-efficient algorithm design by requiring computation of a specific row of Pascal’s triangle without constructing the full triangle.

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Question

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Problem

Given an integer rowIndex (0-indexed), return the rowIndex-th row of Pascal’s triangle.

Pascal’s triangle is defined as:

Row 0 is [1]
Each subsequent row starts and ends with 1
Each interior element is the sum of the two elements directly above it:
- row[i][j] = row[i-1][j-1] + row[i-1][j]

Input

rowIndex : integer ( >= 0 )

Output

An array/list of length rowIndex + 1 containing the values in that row.

Constraints (memory-focused)

0 <= rowIndex <= 10^5
You should use O(rowIndex) extra space (a full 2D triangle may exceed memory limits).

Example

rowIndex = 4 → [1, 4, 6, 4, 1]