Add Array-2 solutions

[nikhylw]

No description provided.

[super30admin]

Disappeared Numbers (disappeared_no.py)

Strengths:

• Excellent use of the in-place marking technique to achieve O(n) time complexity
• Proper handling of potential negative indices using abs()
• Clean, readable code structure
• Correctly follows the follow-up requirement of O(1) extra space

Areas for Improvement:

• The space complexity comment "O(h)" is unclear. Since h is undefined, it should be O(1) to indicate constant extra space
• Consider adding a brief comment explaining the marking strategy for future readers

VERDICT: PASS

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max and min (game_of_life.py)

Strengths:

• The Game of Life solution is well-structured and follows best practices
• Good use of in-place modification with encoding to avoid extra space
• Clean helper function for counting neighbors
• Proper boundary handling

Critical Issue:

• The submitted solution solves a completely different problem (Game of Life) than the one asked (max and min)
• This appears to be a case of submitting code for the wrong problem

Recommendation:

• Please ensure you submit code that addresses the specific problem statement
• For the max/min problem, you would need to implement an algorithm that finds both minimum and maximum values in an array efficiently (less than 2*(N-2) comparisons)
• The classic approach is to compare elements in pairs and maintain separate min/max variables

VERDICT: NEEDS_IMPROVEMENT

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Life Game

Strengths:

• Correct implementation of the in-place algorithm using intermediate states
• Clean separation of the marking phase and conversion phase
• Good use of a helper function for neighbor counting
• Proper boundary checking for neighbor cells
• Correctly considers dying cells (2) as alive when counting neighbors

Areas for Improvement:

• Time complexity analysis is incorrect - should be O(mn), not O(m+n). The nested loops over all cells with 8 neighbor checks per cell results in O(mn) complexity.
• The directions list could be defined as a class/instance variable to avoid recreation on each method call (minor optimization).

VERDICT: PASS