Array Reversal Techniques in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to swap two elements in the array.

DSA C

void swap(int *a, int *b) {
    int temp = *a;
    *a = [1];
    *b = temp;
}

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

Aa

B*b

Ctemp

D*a

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning temp to *a instead of *b.

Using variable names without dereferencing.

The value pointed by b (*b) is assigned to *a to complete the swap.

2fill in blank

medium

Complete the for loop condition to reverse the array by swapping elements.

DSA C

for (int i = 0; i < [1] / 2; i++) {
    swap(&arr[i], &arr[[1] - i - 1]);
}

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

An

Blength

Csize

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variable names for array size.

Looping till the full array length instead of half.

The variable n represents the size of the array and is used to find the midpoint.

3fill in blank

hard

Fix the error in the while loop condition to reverse the array.

DSA C

int start = 0, end = n - 1;
while (start [1] end) {
    swap(&arr[start], &arr[end]);
    start++;
    end--;
}

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

A<

B<=

C>

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= causes swapping the middle element twice.

Using > or >= causes the loop to never run.

The loop should run while start is less than end to avoid swapping the middle element twice.

4fill in blank

hard

Fill both blanks to create a for loop that reverses the array using two indices.

DSA C

for (int i = 0, j = [1] - 1; i < j; i++, [2]--) {
    swap(&arr[i], &arr[j]);
}

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

An

Bsize

Cj

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variable names for array size.

Incrementing j instead of decrementing.

The loop starts with j at n-1 and decrements j each iteration.

5fill in blank

hard

Fill all three blanks to create a function that reverses an array in place.

DSA C

void reverseArray(int arr[], int [1]) {
    int start = 0, end = [2] - 1;
    while (start [3] end) {
        swap(&arr[start], &arr[end]);
        start++;
        end--;
    }
}

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

An

C<

Dsize

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names.

Using <= instead of < in the loop condition.

The function uses n as the parameter name, n for the array length, and < in the while loop condition.