Dynamic Stack Using Resizable Array in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the stack size.

DSA C

stack->capacity = [1];

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

A10

B0

C-1

D100

Attempts:

3 left

💡 Hint

Common Mistakes

Setting capacity to 0 or negative values causes no space allocation.

The initial capacity of the dynamic stack is usually set to a positive number like 10 to allocate space.

2fill in blank

medium

Complete the code to double the stack capacity when resizing.

DSA C

stack->capacity = stack->capacity [1] 2;

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

A/

B*

C-

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of multiplication for doubling.

Doubling capacity means multiplying the current capacity by 2.

3fill in blank

hard

Fix the error in the push function to check if resizing is needed.

DSA C

if (stack->top == stack->capacity [1]) {
    resize_stack(stack);
}

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

A>

B<

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than or less than instead of equality check.

When top equals capacity, the stack is full and needs resizing.

4fill in blank

hard

Fill both blanks to correctly pop an element from the stack.

DSA C

if (stack->top [1] 0) {
    return stack->array[[2]];
} else {
    return -1; // stack empty
}

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

A>

B>=

Cstack->top - 1

Dstack->top

Attempts:

3 left

💡 Hint

Common Mistakes

Checking top >= 0 allows empty stack access.

Using top index directly returns invalid element.

We check if top is greater than 0 to ensure stack is not empty, then return element at top-1 index.

5fill in blank

hard

Fill all three blanks to correctly resize the stack array.

DSA C

int *new_array = malloc(stack->capacity [1] sizeof(int));
for (int i = 0; i [2] stack->top; i++) {
    new_array[i] = stack->array[i];
}
free(stack->array);
stack->array = [3];

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

A*

B<

Cnew_array

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of multiplication for malloc size.

Using i <= top causes out-of-bounds access.

Not assigning new_array back to stack->array.

We allocate new array with capacity * sizeof(int), copy elements while i < top, then assign new_array to stack->array.