Combination Sum IV
mediumblind-75dsadp
Asked at
Flipkart, Meesho, PhonePe, Razorpay, Swiggy
Problem statement
Implement combinationSum4 for the classic Combination Sum IV problem.
This Blind 75 version is framed for frontend interviews: write clean JavaScript, name the invariant out loud, and handle edge cases without over-engineering.
What this tests
- Pattern:
ordered count DP. - Ability to explain time and space complexity clearly.
- Careful handling of empty inputs, duplicates, and boundary cases.
- Production-style JavaScript readability, not just competitive-programming shortcuts.
Requirements & constraints
- Use JavaScript without external libraries.
- Prefer the standard optimal interview approach for this pattern.
- Return deterministic output when multiple valid outputs exist where the prompt implies ordering.
Examples
Example 1
Input: Use the canonical Blind 75 sample for this problem.
Output: Return the value required by the problem statement.
How to approach Combination Sum IV
The strategy an interviewer expects you to reach for.
Senior Frontend Approach Start by identifying the pattern: ordered count DP. Then define the invariant the loop or recursion maintains before writing code.
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