Round 1
Questions:
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- Was asked a variation: If a root-to-leaf path has an even number of negative nodes, the generated number should be added to the overall sum. If the path has an odd number of negative nodes, the generated number should be subtracted from overall sum.
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Kth Largest Element in an Array
- I initially suggested the Min-Heap solution. On being asked if a more optimal solution exists, I suggested the Quick Select solution.
Candidate's Approach
For the first question, I wrote the standard tree traversal approach and incremented a negative nodes counter in each function call. At the leaf nodes, I applied the odd/even logic based on the counter. The time complexity was O(N) and space complexity was O(logN) considering the recursion call stack.
For the second question, I suggested the Quick Select solution with random pivot selection after discussing the Min-Heap solution. The space complexity is O(1) if the recursion stack is not considered, and the average time complexity is O(N), although it can be O(N^2) in the worst case.
Interviewer's Feedback
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