Subsets Generation Using Bitmask in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate the total number of subsets for a set of size n.

DSA C

int total_subsets = 1 << [1];

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An

Bsize

Ccount

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong variable name instead of n.

Using multiplication instead of bit shift.

Using bit shift operator 1 << n calculates 2^n, which is the total number of subsets.

2fill in blank

medium

Complete the for loop to iterate over all subsets represented by bitmasks.

DSA C

for (int mask = 0; mask < (1 << n); mask[1]) {

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A+=

B--

C++

D*=

Attempts:

3 left

💡 Hint

Common Mistakes

Using decrement operator which causes an infinite loop.

Using multiplication or addition incorrectly.

The loop increments mask by 1 each time to cover all subsets from 0 to 2^n - 1.

3fill in blank

hard

Fix the error in the condition to check if the j-th element is included in the current subset mask.

DSA C

if (mask & (1 [1] j)) {

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A>>

B<<

C&

D|

Attempts:

3 left

💡 Hint

Common Mistakes

Using right shift instead of left shift.

Using bitwise OR or AND incorrectly.

To check if the j-th bit is set, shift 1 left by j positions and bitwise AND with mask.

4fill in blank

hard

Fill both blanks to print all elements of the current subset represented by mask.

DSA C

for (int j = 0; j [1] n; j[2]) {
    if (mask & (1 << j)) {
        printf("%d ", arr[j]);
    }
}

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A<

B<=

C++

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= instead of < causing out-of-bounds access.

Using decrement operator causing infinite loop.

The loop runs from j = 0 up to j < n, incrementing j each time to check all elements.

5fill in blank

hard

Fill all three blanks to create a function that generates all subsets of an array using bitmask.

DSA C

void generate_subsets(int arr[], int n) {
    int total = 1 [1] n;
    for (int mask = 0; mask [2] total; mask++) {
        printf("{ ");
        for (int j = 0; j [3] n; j++) {
            if (mask & (1 << j)) {
                printf("%d ", arr[j]);
            }
        }
        printf("}\n");
    }
}

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A<<

B<

C++

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= in loop conditions causing out-of-bounds errors.

Using wrong bit shift direction.

Not incrementing loop variables properly.

Use bit shift to calculate total subsets, loop mask from 0 to total-1, and increment j to check each element.