Merge Sort as Divide and Conquer in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the middle index for dividing the array.

DSA C

int mid = (left [1] right) / 2;

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A*

B-

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction instead of addition

Dividing before adding

The middle index is found by adding left and right, then dividing by 2.

2fill in blank

medium

Complete the recursive call to sort the left half of the array.

DSA C

mergeSort(arr, [1], mid);

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Aleft

B0

Cright

Dmid

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of left

Using right instead of left

The left boundary is passed as the start index for sorting the left half.

3fill in blank

hard

Fix the error in the merge function call to merge two halves correctly.

DSA C

merge(arr, left, [1], right);

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Aright - 1

Bmid - 1

Cleft + 1

Dmid + 1

Attempts:

3 left

💡 Hint

Common Mistakes

Using mid - 1 instead of mid + 1

Using left + 1 incorrectly

The middle index plus one is the start of the right half for merging.

4fill in blank

hard

Fill both blanks to complete the loop copying elements back to the original array.

DSA C

for (int k = [1]; k <= [2]; k++) {
    arr[k] = temp[k];
}

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

Aleft

Bmid

Cright

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Starting from 0 instead of left

Ending at mid instead of right

The loop copies elements from left to right indices back to the original array.

5fill in blank

hard

Fill all three blanks to complete the merge function's main merging loop.

DSA C

while (i <= [1] && j <= [2]) {
    if (arr[i] <= arr[j]) {
        temp[k++] = arr[[3]++];
    } else {
        temp[k++] = arr[j++];
    }
}

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

Amid

Bright

Ci

Dleft

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong boundary values

Incrementing wrong index

The loop runs while i is less or equal to mid and j less or equal to right. The element at i is copied and i is incremented.