Stock Span Problem Using Stack in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the stack array for storing indices.

DSA C

int stack[[1]];

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A0

B10

C-1

D1000

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or negative size for the stack array.

Using too small size like 10 which may not hold all indices.

The stack size should be large enough to hold all indices, so 1000 is a safe choice.

2fill in blank

medium

Complete the code to initialize the top of the stack.

DSA C

int top = [1];

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A-1

B0

C1

D1000

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing top to 0 which means stack is not empty.

Using a large number like 1000 which is out of bounds.

The top is initialized to -1 to indicate the stack is empty.

3fill in blank

hard

Fix the error in the while loop condition to pop prices less than or equal to the current price from the stack.

DSA C

while (top >= 0 && prices[stack[top]] [1] prices[i]) {
    top--;
}

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

A<

B>=

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' which does not pop equal prices.

Using '>=' or '>' which reverses the logic.

We pop while the price at stack top is less than or equal to the current price.

4fill in blank

hard

Fill both blanks to calculate the span correctly.

DSA C

span[i] = (top == -1) ? [1] : i - stack[2];

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Ai + 1

Bi - 1

C[top]

D[top - 1]

Attempts:

3 left

💡 Hint

Common Mistakes

Using i - 1 instead of i + 1 for empty stack case.

Using stack[top - 1] which may cause wrong index.

If stack is empty, span is i+1; else span is difference between current index and top index in stack.

5fill in blank

hard

Fill all three blanks to push current index onto stack and print the spans.

DSA C

stack[++top] = [1];

for (int j = 0; j < n; j++) {
    printf("%d ", [2][[3]]);
}

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

Ai

Bspan

Cj

Dprices

Attempts:

3 left

💡 Hint

Common Mistakes

Pushing wrong variable onto stack.

Printing prices instead of span.

Using wrong loop variable in print.

Push current index i onto stack; print span[j] for all j from 0 to n-1.