Find Maximum Subarray Divide and Conquer in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the middle index of the array segment.

DSA C

int mid = (low + [1]) / 2;

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Amid

Bhigh

Clow

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using low twice instead of high.

Using mid variable before assignment.

The middle index is calculated by adding low and high indices and dividing by 2.

2fill in blank

medium

Complete the code to return the maximum of two integers.

DSA C

int max = (a > [1]) ? a : b;

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A0

Ba

Cmax

Db

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing a with itself.

Returning wrong variable.

We compare a and b, returning the greater value.

3fill in blank

hard

Fix the error in the loop that finds maximum crossing subarray sum.

DSA C

for (int i = mid; i >= [1]; i--) {
    sum += arr[i];
    if (sum > left_sum) left_sum = sum;
}

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

Alow

Bhigh

Cmid

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using high instead of low.

Loop direction incorrect.

The loop should run from mid down to low index to cover left half.

4fill in blank

hard

Fill both blanks to correctly compute the maximum crossing subarray sum.

DSA C

int right_sum = INT_MIN;
int sum = 0;
for (int j = mid + 1; j <= [1]; j++) {
    sum += arr[j];
    if (sum > [2]) right_sum = sum;
}

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

Ahigh

Bright_sum

Cleft_sum

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Using left_sum instead of right_sum.

Comparing with wrong variable.

The loop runs from mid+1 to high. We compare sum with right_sum to update it.

5fill in blank

hard

Fill all three blanks to return the maximum subarray sum among left, right, and crossing sums.

DSA C

return [1](left_sum, [2](right_sum, [3]));

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

Amax

Bleft_sum

Cright_sum

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Using sum instead of max.

Wrong order of arguments.

We use max function twice to find the maximum among three sums.