Java Array Manipulation and In-Place Algorithm Quiz Quiz

1. Understanding the Remove Element Problem

   In an in-place array manipulation algorithm that removes all occurrences of a specific value, what does the function typically return?

   1. The count of remaining valid elements
   2. The entire modified array
   3. The index of the last valid element
   4. The number of removed elements
   5. A boolean indicating success

2. Two-Pointer Technique Basics

   When using the two-pointer technique to remove elements from an array in Java, what is an efficient approach to avoid extra memory usage?

   1. Modify the array itself without using additional space
   2. Create a new list to store results
   3. Use recursion to track positions
   4. Copy valid elements to a secondary array
   5. Store indices in a separate array

3. Code Reading: Array Updates

   Given nums = [0,1,2,2,3,0,4,2] and val = 2, after removing all occurrences of 2, how many valid elements remain?

   1. 5
   2. 4
   3. 6
   4. 7
   5. 3

4. Time Complexity Recognition

   What is the time complexity of an algorithm that removes all occurrences of a given value from an array by inspecting each element once?

   1. O(n)
   2. O(1)
   3. O(n^2)
   4. O(log n)
   5. O(n log n)

5. Space Complexity Application

   What is the required additional space complexity for the optimal in-place removal of elements from an array?

   1. O(1)
   2. O(n)
   3. O(log n)
   4. O(n^2)
   5. O(k) where k is number of removals

6. Identifying Algorithm Output

   Suppose an array is updated in place and the function returns an integer k, which describes the final state. What does k represent?

   1. Number of elements not equal to the removed value
   2. Position of the last element
   3. Total sum of the array
   4. Index of the removed value
   5. Number of removed elements

7. Option Recognition with Typos

   Which of the following is the correct signature for a Java method removing elements in-place from an array and returning the count?

   1. public int removeElement(int[] nums, int val)
   2. public void removeElement(int[] nums, int val)
   3. public int removeElemnt(int[] nums, int val)
   4. private int removeElement(int nums[], int value)
   5. public int removeItems(int[] num, int value)

8. Algorithm Logic: Loop Usage

   In the in-place removal algorithm for arrays, which type of loop is commonly used to iterate through the array?

   1. A for-loop that processes each element once
   2. A recursive while-loop
   3. A do-while loop with infinite iterations
   4. A nested for-loop for each value
   5. An enhanced for-each loop that auto-removes elements

9. Typical Pitfall in In-Place Removal

   What is a common mistake when modifying arrays in place while removing elements?

   1. Skipping elements after removal
   2. Using extra memory for valid items
   3. Decreasing the value of all remaining elements
   4. Changing the data type of the array
   5. Using a for-each loop instead of a for loop

10. Conceptual Understanding: Array Elements

    Why is the order of elements important in the in-place removal problem, and how should it be maintained?

    1. Order should remain as in the original array for all valid elements
    2. Order does not matter at all
    3. Order should be reversed
    4. All elements should be sorted after removal
    5. Elements with the removed value should come first