Completed Binary-Search-2

[sangeeths29]

No description provided.

[super30admin]

The student has provided solutions to three binary search problems. Here's my evaluation for each:

1. Find First and Last Position of Element in Sorted Array:

• Correctness: The solution correctly implements two binary searches to find the first and last positions. The logic for moving left/right when duplicates are found is correct.
• Time Complexity: O(log n) for both searches, which is optimal.
• Space Complexity: O(1), using constant space.
• Code Quality: Well-structured with clear helper functions. Could improve by adding docstrings.
• Edge Cases: Handles empty array and target not found cases well.

2. Find Minimum in Rotated Sorted Array:

• Correctness: The solution correctly identifies the minimum by checking sorted halves and pivot points.
• Time Complexity: O(log n), which is optimal.
• Space Complexity: O(1).
• Code Quality: Good, but the condition nums[l] <= nums[r] could be moved before the while loop since it's checked in every iteration.
• Edge Cases: Handles empty array and single-element cases, but could fail if array is not rotated (already sorted).

3. Find Peak Element:

• Correctness: Correctly implements binary search to find a peak element.
• Time Complexity: O(log n), optimal.
• Space Complexity: O(1).
• Code Quality: Good, but the condition checking could be simplified.
• Edge Cases: Handles edge cases well, including single-element arrays.

General Improvements:

1. Add docstrings to explain each function's purpose and parameters.
2. Consider adding more test cases, especially for edge cases.
3. For Problem 2, the initial check for sorted array could be done once before the loop.
4. Consistent error handling (e.g., all functions return -1 for invalid cases).