Reverse Bits of a Number in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the result variable to zero.

DSA C

unsigned int reverseBits(unsigned int n) {
    unsigned int result = [1];
    for (int i = 0; i < 32; i++) {
        // loop body
    }
    return result;
}

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

An

B1

C-1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing result with n instead of 0.

Using negative values for unsigned int.

We start with result = 0 because we will build the reversed bits from scratch.

2fill in blank

medium

Complete the code to extract the least significant bit of n.

DSA C

unsigned int reverseBits(unsigned int n) {
    unsigned int result = 0;
    for (int i = 0; i < 32; i++) {
        unsigned int bit = n [1] 1;
        n >>= 1;
        // use bit
    }
    return result;
}

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A&

B<<

C^

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using OR or XOR instead of AND to extract bits.

Using shift operators incorrectly here.

Using bitwise AND with 1 extracts the least significant bit of n.

3fill in blank

hard

Fix the error in the code to shift the result left before adding the extracted bit.

DSA C

unsigned int reverseBits(unsigned int n) {
    unsigned int result = 0;
    for (int i = 0; i < 32; i++) {
        unsigned int bit = n & 1;
        n >>= 1;
        result = (result [1] 1) | bit;
    }
    return result;
}

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A>>

B<<

C+

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using right shift instead of left shift.

Using addition instead of bitwise OR.

We shift result left by 1 to make space for the new bit on the right.

4fill in blank

hard

Fill both blanks to complete the loop that reverses bits of n.

DSA C

unsigned int reverseBits(unsigned int n) {
    unsigned int result = 0;
    for (int i = 0; i [1] 0; i [2] 32) {
        unsigned int bit = n & 1;
        n >>= 1;
        result = (result << 1) | bit;
    }
    return result;
}

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A=

B<

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using > or <= incorrectly in the loop condition.

Starting i at 1 instead of 0.

The loop starts with i = 0 and runs while i < 32 to process all bits.

5fill in blank

hard

Fill all three blanks to create a function that reverses bits of an unsigned int.

DSA C

unsigned int reverseBits(unsigned int n) {
    unsigned int result = [1];
    for (int i = 0; i [2] 0; i [3] 32) {
        unsigned int bit = n & 1;
        n >>= 1;
        result = (result << 1) | bit;
    }
    return result;
}

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

A0

B=

C<

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to initialize result to zero.

Using wrong loop conditions or increments.

Initialize result to 0, start i at 0, loop while i < 32, and increment i by 1 each time.