Check if Stack is Empty or Full in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the stack is empty.

DSA C

int isEmpty(int top) {
    return top [1] -1;
}

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

A>

B==

C!=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment '=' instead of comparison '=='

Checking if top is greater than -1 instead of equal

The stack is empty when the top index is equal to -1.

2fill in blank

medium

Complete the code to check if the stack is full given MAX size.

DSA C

int isFull(int top) {
    return top [1] MAX - 1;
}

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

A>

B<

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '>' instead of '=='

Comparing top with MAX instead of MAX - 1

The stack is full when the top index equals MAX - 1.

3fill in blank

hard

Fix the error in the function that checks if the stack is empty.

DSA C

int isEmpty(int top) {
    if (top [1] -1) {
        return 1;
    } else {
        return 0;
    }
}

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

A==

B=

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment '=' inside if condition

Confusing '==' with '='

The condition should use '==' to compare top with -1, not '=' which assigns.

4fill in blank

hard

Fill both blanks to correctly check if the stack is full or empty.

DSA C

int checkStack(int top) {
    if (top [1] -1) {
        return 0; // empty
    } else if (top [2] MAX - 1) {
        return 1; // full
    }
    return -1; // neither
}

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

A==

B=

C!=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment '=' instead of comparison '=='

Using '!=' or '>' which give wrong results

Use '==' to compare top with -1 for empty and with MAX - 1 for full.

5fill in blank

hard

Fill all three blanks to implement a function that returns a string status of the stack.

DSA C

const char* stackStatus(int top) {
    if (top [1] -1) {
        return "Empty";
    } else if (top [2] MAX - 1) {
        return "Full";
    } else if (top [3] -1 && top [3] MAX - 1) {
        return "Has Space";
    }
    return "Invalid";
}

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

A==

B!=

C<

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '>' instead of '!=' in last condition

Mixing assignment '=' with comparison operators

Check if top equals -1 for empty, equals MAX - 1 for full, and is not equal to either for having space.