Debugging During Live Coding | Dataford Interview Questions

Discuss your approach to debugging a piece of code during a live coding session.

In the exercise, inspect and correct a function that should return the first value appearing twice in an integer array. Explain how you reproduce the failure, isolate the cause, validate the fix, and consider edge cases.

Implement find_first_duplicate(nums). Return the first repeated value, or None if every value is unique.

Constraints

0 <= len(nums) <= 10^4
-10^9 <= nums[i] <= 10^9
Return the value whose second occurrence appears earliest
Return None when no value is repeated

Function Signature

def find_first_duplicate(nums):

Your question is Debugging During Live Coding. 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.

Problem

Discuss your approach to debugging a piece of code during a live coding session.

Implement find_first_duplicate(nums). Return the first repeated value, or None if every value is unique.

Constraints

0 <= len(nums) <= 10^4
-10^9 <= nums[i] <= 10^9
Return the value whose second occurrence appears earliest
Return None when no value is repeated

Function Signature

def find_first_duplicate(nums):

Your question is Debugging During Live Coding. 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.