Reverse Bits of a Number in DSA Python - Practice Problems & Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of reversing bits of 13 in 8-bit representation?

Given the 8-bit binary representation of the number 13, what is the decimal value after reversing its bits?

DSA Python

def reverse_bits(n, bits=8):
    result = 0
    for _ in range(bits):
        result = (result << 1) | (n & 1)
        n >>= 1
    return result

print(reverse_bits(13))

A 176

B 212

C 134

D 104

💡 Hint

Think about the binary form of 13: 00001101. Reverse the bits and convert back to decimal.

13 in 8 bits is 00001101. Reversing bits gives 10110000 which is 176 in decimal.

❓ Predict Output

intermediate

What is the output of reversing bits of 1 in 4-bit representation?

What decimal number results from reversing the bits of 1 using 4 bits?

DSA Python

def reverse_bits(n, bits=4):
    result = 0
    for _ in range(bits):
        result = (result << 1) | (n & 1)
        n >>= 1
    return result

print(reverse_bits(1, 4))

A 2

B 4

C 1

D 8

💡 Hint

1 in 4 bits is 0001. Reverse bits and convert to decimal.

0001 reversed is 1000 which equals 8 in decimal.

🔧 Debug

advanced

What error does this code raise when reversing bits?

Identify the error raised by this code snippet when reversing bits of 5 in 3 bits:

DSA Python

def reverse_bits(n, bits=3):
    result = 0
    for i in range(bits):
        result = (result << 1) | (n & 1)
        n = n >> 1
    return result

print(reverse_bits(5))

A No error, output is 5

B IndexError

C SyntaxError

D TypeError

💡 Hint

Check if the code runs without exceptions and what output it produces.

The code correctly reverses bits of 5 (101) in 3 bits to 101 which is 5 decimal. No error occurs.

❓ Predict Output

advanced

What is the output of reversing bits of 19 in 5-bit representation?

Calculate the decimal value after reversing the 5-bit binary representation of 19.

DSA Python

def reverse_bits(n, bits=5):
    result = 0
    for _ in range(bits):
        result = (result << 1) | (n & 1)
        n >>= 1
    return result

print(reverse_bits(19, 5))

A 13

B 25

C 22

D 17

💡 Hint

19 in 5 bits is 10011. Reverse bits and convert to decimal.

10011 reversed is 11001 which equals 25 decimal.

🧠 Conceptual

expert

How many bits are needed to reverse bits of the number 1023 correctly?

To reverse the bits of the number 1023 correctly, how many bits should be used in the reversal process?

A 16 bits

B 8 bits

C 10 bits

D 12 bits

💡 Hint

Think about the binary length of 1023.

1023 in binary is 1111111111 which is 10 bits long, so 10 bits are needed to reverse it correctly.