Binary Search 1 Solutions Posted

[angad-singh97]

No description provided.

[super30admin]

Search in Rotated Sorted Array (02-search-rotated-sorted-array.cpp)

Strengths:

• Excellent understanding of the binary search approach for rotated arrays
• Clean implementation with good variable naming (lo, hi, mid)
• Well-documented with time/space complexity analysis
• Honest self-reflection about learning from the problem
• Correctly handles the edge case of single-element arrays

Areas for Improvement:

• The else-if condition nums[mid] <= nums[lo] can be simplified to just else since the right half is guaranteed to be sorted if the left half isn't
• Consider adding early return optimization (though current approach is already optimal)
• The comment about being "disappointing" is too harsh - recognizing the pattern is a skill that develops with practice

Overall Assessment:
This is a solid, correct implementation that matches the reference solution in both correctness and efficiency. The student demonstrates good problem-solving skills and proper algorithm analysis.

VERDICT: PASS

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Search in a Sorted Array of Unknown Size (03-search-infinite-sorted-array.cpp)

Strengths:

1. Excellent understanding of the problem - correctly identified the need for exponential expansion to find bounds
2. Clean implementation with proper variable naming
3. Good use of overflow-safe mid-point calculation
4. Well-documented with time/space complexity comments
5. Thoughtful acknowledgment of the boundary condition handling with INT_MAX

Areas for Improvement:

1. The solution is functionally identical to the reference solution - consider if there's a way to make it more distinctive or add value
2. Minor optimization opportunity: Store reader.get(mid) result in a variable to avoid redundant API calls (currently calling it 3 times per iteration in worst case)
3. Could add more detailed comments explaining why we start hi at 1 and double it

Overall, this is a solid, correct implementation that matches the reference solution in both approach and efficiency.

VERDICT: PASS

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Search a 2D Matrix (01-search-2d-array.cpp)

Strengths:

• Correct implementation of the binary search algorithm on a 2D matrix
• Excellent self-awareness about the trickiest part (using division and modulo to map indices)
• Clean, readable code with appropriate comments
• Proper handling of edge cases (single element, target at boundaries)
• Good variable naming conventions

Areas for Improvement:

• The assumedSize variable on line 9 is declared but never used - consider removing it for cleaner code
• The solution is already optimal; no algorithmic improvements needed

Note on Learning Strategy:
The student's comment about needing "more closely spaced repetition" for remembering the division/modulo trick is excellent self-reflection. This is a common pattern in algorithm problems, and creating a mental model of how indices map between 1D and 2D representations can help solidify this concept.

VERDICT: PASS