dp-2 solutions

[nikhylw]

No description provided.

[super30admin]

Paint House (paint_house.py)

Strengths:

1. Excellent use of dynamic programming - optimal substructure and overlapping subproblems identified correctly
2. Clean, readable code with meaningful variable names (red, blue, green)
3. Constant space complexity - very memory efficient
4. Linear time complexity - much better than the reference's exponential approach
5. Proper handling of edge cases (empty input)
6. Good inline comments explaining complexity

Areas for Improvement:

1. Consider adding type hints for better code documentation (e.g., costs: List[List[int]])
2. Could add a brief docstring explaining the algorithm
3. The variable reassignment on one line is slightly less readable; could split for clarity

Minor Note:
The solution assumes the input will always have exactly 3 colors per house, which matches the problem constraints, so this is not an issue.

VERDICT: PASS

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Coin Change II (coin_change_2.py)

Strengths:

1. Excellent use of dynamic programming - the solution is much more efficient than the reference recursive solution
2. Clean, readable code with appropriate comments explaining complexity
3. Correct DP formulation with proper base case (dp[0] = 1)
4. Proper use of type hints for better code documentation
5. The outer loop over coins ensures combinations (not permutations) are counted

Areas for Improvement:

1. The solution is already optimal for this problem - no significant improvements needed
2. Could add a small optimization: early return if amount is 0 (returns 1 immediately)
3. Could consider adding input validation for edge cases (though constraints guarantee valid input)

VERDICT: PASS