**Why In-Place Reversal:** O(n) time, O(1) space. Recursive version uses O(n) stack—fails for long lists (stack overflow). **Algorithm:** Iterate, reverse next pointers: save next, point current to prev, advance prev and curr. Handles empty and single-node. **Analogy in Data...
This easy-level Python/Coding question appears frequently in data engineering interviews at companies like Paytm. While less common, it tests deeper understanding that distinguishes strong candidates.
Start by clearly defining the core concept being asked about. Interviewers want to see that you understand the fundamentals before diving into implementation details. Structure your answer with a definition, then explain the practical application with a concise example.
Why In-Place Reversal: O(n) time, O(1) space. Recursive version uses O(n) stack—fails for long lists (stack overflow).
Algorithm: Iterate, reverse next pointers: save next, point current to prev, advance prev and curr. Handles empty and single-node.
Analogy in Data Eng: Reverse order of events (LIFO processing), undo stacks. Conceptually similar to reversing a stream buffer—process from tail.
def reverse_list(head):
prev = None
while head:
nxt = head.next
head.next = prev
prev, head = head, nxt
return prev
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Analyze My Answer — FreeAccording to DataEngPrep.tech, this is one of the most frequently asked Python/Coding interview questions, reported at 1 company. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.