Completed Binary Search 1 course

[sanjoli97]

No description provided.

[super30admin]

Search inside a Rotated Sorted Array (SearchRotatedSortedArray.java)

The student has not attempted to solve the problem. They need to:

1. Implement the binary search algorithm for a rotated sorted array
2. Handle the case where the array is rotated at an unknown pivot
3. Use the standard binary search pattern with appropriate conditions to determine which half is sorted
4. Return the index if found, or -1 if not found

The reference solution shows the correct approach:

• Use two pointers (low and high) for binary search
• At each step, determine which half of the array is sorted
• Based on which half is sorted, determine if the target could be in that half
• Adjust pointers accordingly

Since this is a class declaration only with no implementation, the student has not demonstrated any understanding of the problem or solution approach.

VERDICT: NEEDS_IMPROVEMENT

---

Search Inside a Sorted Array whose Length is unknown (Search.java)

Strengths:

• Excellent implementation that matches the reference solution exactly
• Well-documented with clear comments explaining the algorithm
• Clean and readable code structure
• Correctly handles edge cases (target not found, out-of-bounds access)

Areas for Minor Improvement:

• The comment "O(2log n) = O(log n)" is technically correct but could be simplified to just "O(log n)"
• Could add a brief comment explaining why we use high * 2 (doubling strategy for exponential search)

Overall, this is a solid implementation that demonstrates good understanding of binary search with unknown array bounds.

VERDICT: PASS

---

Search a 2D Matrix (SearchMatrix.java)

Strengths:

• Correctly implements binary search on a 2D matrix with O(log(m*n)) time complexity
• Uses proper variable naming (row, col, low, high, mid, r, c)
• Includes helpful comments explaining the approach
• Handles the mid calculation safely with low + (high - low)/2 to prevent integer overflow
• Clean and readable code structure

Areas for Improvement:

• The comment states "O(log n + log m)" but this is not equivalent to O(log(mn)). While mathematically they are the same (log(m) + log(n) = log(mn)), it would be clearer to state O(log(mn)) or O(log(mn)) to match the problem requirement
• Could add a null/empty check for robustness, though the constraints guarantee non-empty matrix
• The variable declaration int row = matrix.length;; has a double semicolon which should be cleaned up

Efficiency:
The solution is already optimal with O(log(m*n)) time and O(1) space complexity. No further optimizations are needed.

VERDICT: PASS