Java Bit Manipulation u0026 Algorithms Audio Quiz Quiz

1. Understanding the XOR Operator

   Which statement best describes what happens when you apply the XOR (^) operator to two identical bits in Java?

   1. The result is always zero.
   2. Both bits are inverted.
   3. The result is always one.
   4. The smaller bit is returned.
   5. Nothing changes; the bits remain the same.

2. Detecting a Missing Element

   Given an array with numbers in the range 0 to n and one missing number, which bitwise approach helps identify the missing value with O(1) space complexity?

   1. XOR all indices and array elements together.
   2. Sum all elements and subtract from the expected total.
   3. Sort the array first and look for gaps.
   4. Check every pair of numbers for the missing one.
   5. Use division on all numbers.

3. Minimizing Space Complexity

   Which method enables you to find a missing number in an array without using any extra space in Java?

   1. Use a single variable and the XOR operator in a loop.
   2. Create a new array to store checked values.
   3. Sort the array and check sequentially.
   4. Use a Set to store all elements.
   5. Recursively compare elements.

4. Analyzing Time Complexity

   In the context of searching for a missing array element using XOR, what is the overall time complexity of the optimal solution?

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

5. Correct Syntax for XOR

   Which of the following Java statements correctly applies the XOR operator between two integers a and b?

   1. int result = a ^ b;
   2. int result = a xor b;
   3. int result = a u0026u0026 b;
   4. int result = a | b;
   5. int result = a ^^ b;

6. Use of Sets in Brute Force Search

   How can a Set be used to find a missing number from an array in Java?

   1. Store all array elements in a Set and check each number in the range.
   2. Store only unique numbers in a Set and return its size.
   3. Replace the array with a Set and sort it.
   4. Insert zero and then check for missing numbers.
   5. Sets cannot help in this scenario.

7. Bitwise Operation Results

   What does the following Java operation output if x = 5 and y = 5: System.out.println(x ^ y);?

   1. 0
   2. 1
   3. 5
   4. 10
   5. 25

8. Typos and Syntax Errors

   Which of the following is an incorrect way to use the XOR operator in Java?

   1. res = res ^ num;
   2. result ^= value;
   3. res = res XOR value;
   4. int answer = a ^ b;
   5. answer ^= elem;

9. Reducing Number of Loops

   What is the primary benefit of combining the loops when using bitwise XOR to find a missing element?

   1. It reduces the total number of operations.
   2. It automatically sorts the array.
   3. It increases space complexity.
   4. It doubles the time complexity.
   5. It makes the code harder to understand.

10. XOR Properties in Practice

    If res starts at zero, and you XOR all numbers from 1 to n and all elements of an array with one missing number (from 1 to n), what does res contain at the end?

    1. The missing number
    2. Zero
    3. The largest number in the array
    4. The total sum of all numbers
    5. All numbers combined together