Check if Number is Even or Odd Using Bits in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if a number is even using bitwise AND.

DSA Python

def is_even(num):
    return (num & [1]) == 0

print(is_even(4))  # True
print(is_even(7))  # False

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

A1

B0

C2

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as mask always returns 0, which is incorrect.

Using the number itself as mask causes errors.

The least significant bit (LSB) of an even number is 0. Using bitwise AND with 1 checks this bit.

2fill in blank

medium

Complete the code to check if a number is odd using bitwise AND.

DSA Python

def is_odd(num):
    return (num & [1]) == 1

print(is_odd(5))  # True
print(is_odd(8))  # False

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

A0

Bnum

C2

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as mask always returns 0.

Using 2 as mask checks wrong bit.

Odd numbers have the least significant bit set to 1. Bitwise AND with 1 checks this.

3fill in blank

hard

Fix the error in the code to correctly check if a number is even using bits.

DSA Python

def check_even(num):
    if (num & [1]) == 0:
        return True
    else:
        return False

print(check_even(10))  # Should be True
print(check_even(7))   # Should be False

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

A1

B2

C0

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Checking if (num & 1) == 1 means odd, not even.

Using wrong mask value.

For even numbers, the last bit is 0, so (num & 1) == 0 means even.

4fill in blank

hard

Fill both blanks to create a function that returns 'Even' or 'Odd' using bitwise operation.

DSA Python

def even_or_odd(num):
    if (num & [1]) == [2]:
        return 'Even'
    else:
        return 'Odd'

print(even_or_odd(12))  # Even
print(even_or_odd(15))  # Odd

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

A1

B0

C2

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping mask and comparison values.

Using incorrect mask value.

Check last bit with 1; if result is 0, number is even; else odd.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that labels numbers as 'Even' or 'Odd' using bits.

DSA Python

numbers = [1, 2, 3, 4, 5]
result = {num: 'Even' if (num & [1]) == [2] else 'Odd' for [3] in numbers}
print(result)

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

A1

B0

Cnum

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong iteration variable.

Incorrect mask or comparison values.

Use 1 as mask, compare to 0 for even, and iterate with variable 'num'.