Precourse-2 Done

[ManishaRana1195]

No description provided.

[super30admin]

1. Exercise_1.java (Binary Search):

   • Correctness: The implementation correctly follows the binary search algorithm. It handles edge cases like an empty array and correctly returns -1 if the element is not found.
   • Time Complexity: O(log n) as stated, which is correct for binary search.
   • Space Complexity: O(1) as stated, which is correct since no additional space is used.
   • Code Quality: The code is clean and well-structured. The comments are helpful and the logic is easy to follow.
   • Efficiency: The implementation is efficient. One minor improvement could be to use mid = l + (r - l) / 2 to avoid potential integer overflow, though it's unlikely to be an issue here.

2. Exercise_2.java (QuickSort):

   • Correctness: The implementation has a logical error in the partition method. The pivot element should be swapped with the low index after the loop, not with high. This causes incorrect sorting.
   • Time Complexity: O(n log n) average case and O(n^2) worst case, as stated, which is correct for QuickSort.
   • Space Complexity: O(1) as stated, which is correct for in-place QuickSort.
   • Code Quality: The code is well-structured and readable. The comments are helpful.
   • Efficiency: The partition logic needs to be fixed to ensure correct sorting. The current implementation will not sort the array correctly.

3. Exercise_3.java (Linked List Middle Element):

   • Correctness: The implementation correctly finds the middle element of the linked list using the slow and fast pointer technique. It handles edge cases like an empty list or a single-node list.
   • Time Complexity: O(n) as stated, which is correct.
   • Space Complexity: O(1) as stated, which is correct.
   • Code Quality: The code is clean and well-structured. The comments are helpful.
   • Efficiency: The implementation is efficient. One minor improvement could be to initialize fast as head instead of slow.next.next to handle cases where the list has only two nodes more elegantly.

4. Exercise_4.java (MergeSort):

   • Correctness: The implementation correctly follows the MergeSort algorithm. It handles the merging of subarrays correctly and sorts the array as expected.
   • Time Complexity: O(n log n) as stated, which is correct.
   • Space Complexity: O(n) as stated, which is correct for the auxiliary arrays used in merging.
   • Code Quality: The code is well-structured and readable. The comments are helpful.
   • Efficiency: The implementation is efficient. One minor improvement could be to reuse a single auxiliary array to reduce space usage, but this is not a major issue.

5. Exercise_5.java (Iterative QuickSort):

   • Correctness: The implementation has the same logical error in the partition method as Exercise_2.java. The pivot element should be swapped with the low index after the loop, not with high. This causes incorrect sorting.
   • Time Complexity: O(n log n) average case and O(n^2) worst case, as stated, which is correct for QuickSort.
   • Space Complexity: O(1) as stated, which is correct for in-place QuickSort.
   • Code Quality: The code is well-structured and readable. The comments are helpful.
   • Efficiency: The partition logic needs to be fixed to ensure correct sorting. The current implementation will not sort the array correctly.

General Feedback:

• The student has a good understanding of algorithms and their complexities. The code is generally well-structured and readable.
• The main issue is with the QuickSort implementations (both recursive and iterative), where the partition logic is incorrect. This needs to be fixed to ensure the sorting works as expected.
• The student should also consider edge cases more thoroughly, such as handling duplicate elements in QuickSort or very small arrays in MergeSort.