Implement Peak Element, Rotated Array Search And Find First And Last Position Of Element

[ayushcha2701]

… position of element

[super30admin]

Find the First and Last Position of an Element in given Sorted Array (FindLastAndFirst.java)

Strengths:

• Clean, well-structured code with good readability
• Proper handling of edge cases (empty array, null check)
• Correct implementation of binary search for both first and last positions
• Uses standard binary search patterns correctly
• Good use of boundary checks (mid == 0, mid == length-1)

Areas for Improvement:

• Consider optimizing the last element search by starting the search from the first position found (as shown in the reference solution). This could reduce comparisons in cases where the target appears multiple times.
• The null check nums == null is good, but in Java, an array parameter won't be null if the method is called correctly from a typical LeetCode-style environment. However, it's still defensive programming and acceptable.

Overall, this is a solid solution that correctly solves the problem with optimal time and space complexity.

VERDICT: PASS

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Find the Minimum Element in a Rotated Array(sorted) (MinimumINRotatedSortedArray.java)

Strengths:

1. Clean and concise implementation of binary search
2. Proper boundary checking (mid > 0) before accessing previous element
3. Good use of standard binary search patterns
4. Clear variable naming makes the logic easy to follow
5. Correctly handles edge cases like non-rotated arrays

Areas for Improvement:

1. The solution is functionally equivalent to the reference and doesn't need major changes
2. Minor suggestion: Could add a brief comment explaining the logic for better readability
3. The return -1 at the end is unnecessary since the problem guarantees a valid input, but it doesn't affect correctness

Overall, this is a solid implementation that demonstrates good understanding of binary search applied to rotated sorted arrays.

VERDICT: PASS

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Find the Peak Element (PeakElement .java)

Strengths:

• Correctly implements binary search for peak element finding
• Handles array boundaries properly (first and last elements)
• Clean and readable code structure
• Good variable naming conventions
• Proper use of left + (right - left) / 2 to prevent potential integer overflow

Areas for Improvement:

• The condition mid != nums.length in the else-if branch is redundant since mid can never reach nums.length (the maximum index is nums.length - 1). This check can be removed for cleaner code.
• Consider adding comments to explain the binary search logic, especially the reasoning behind moving left or right based on neighbor comparisons.

VERDICT: PASS