Find the Only Non Repeating Element Using XOR in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the result variable for XOR operation.

DSA Python

def find_non_repeating(arr):
    result = [1]
    for num in arr:
        result ^= num
    return result

Drag options to blanks, or click blank then click option'

ANone

B1

C0

Darr[0]

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing result with arr[0] causes skipping the first element in XOR.

We start with 0 because XOR with 0 returns the other number unchanged.

2fill in blank

medium

Complete the code to XOR each element with the result.

DSA Python

def find_non_repeating(arr):
    result = 0
    for num in arr:
        result [1]= num
    return result

Drag options to blanks, or click blank then click option'

A&

B+

C|

D^

Attempts:

3 left

💡 Hint

Common Mistakes

Using + or & instead of ^ changes the logic and output.

The XOR operator is ^ in Python, used to find the unique element.

3fill in blank

hard

Fix the error in the function call to print the unique element.

DSA Python

arr = [2, 3, 5, 4, 5, 3, 4]
print(find_non_repeating[1]arr[2])

Drag options to blanks, or click blank then click option'

A[, ]

B(, )

C{, }

D<, >

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or braces instead of parentheses for function calls.

Function calls require parentheses around arguments.

4fill in blank

hard

Fill both blanks to complete the function that returns the unique element from the list.

DSA Python

def find_non_repeating(arr):
    result = [1]
    for num in arr:
        result [2]= num
    return result

Drag options to blanks, or click blank then click option'

A0

B1

C+

D^

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of ^ changes the logic.

Initialize result to 0 and use ^= to XOR each element.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps each number to its XOR with 1 if it is greater than 2.

DSA Python

result = {num: num[1]1 for num in arr if num [2] 2}
filtered = {k: v for k, v in result.items() if v [3] 0}

Drag options to blanks, or click blank then click option'

A^

B>

C!=

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using & instead of ^ for XOR, or == instead of != for filtering.

Use XOR (^) with 1, filter numbers greater than 2, and keep those with XOR result not equal to 0.