Greedy Algorithms - Remove K Digits (Smallest Number)
Suppose the problem is modified so that digits can be removed multiple times (i.e., digits can be reused after removal). Which approach is best suited to solve this variant efficiently?
Suppose the problem is modified so that digits can be removed multiple times (i.e., digits can be reused after removal). Which approach is best suited to solve this variant efficiently?
hard🎤 Interviewer Follow-up Q10 of Q15
Step-by-Step Solution
Solution:
Step 1: Understand the variant
Digits can be removed multiple times, so order and reuse complicate greedy stack approach.Step 2: Greedy with two pointers and string builder allows efficient reuse
This approach can handle repeated removals by scanning and building result dynamically.Final Answer:
Option C -> Option CQuick Check:
Two pointers approach adapts better to reuse than stack [OK]
Quick Trick: Reuse requires dynamic scanning, two pointers fit better [OK]
Common Mistakes:
MISTAKES- Applying monotonic stack blindly
- Using brute force which is infeasible
Trap Explanation:
PITFALL- Candidates often try to reuse monotonic stack approach which fails with digit reuse constraints.
Interviewer Note:
CONTEXT- Tests candidate's ability to adapt approach to problem variants.
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