Find Middle Element of Linked List in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a pointer to traverse the linked list.

DSA C

struct Node* [1] = head;

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Atemp

Bmiddle

Ccurrent

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Using a pointer name that is not declared or inconsistent.

Not initializing the pointer to head.

We use a temporary pointer named temp to traverse the linked list from the head.

2fill in blank

medium

Complete the code to move the slow pointer one step forward in the linked list.

DSA C

slow = slow[1];

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A->next->next

B->next

C->prev

D->data

Attempts:

3 left

💡 Hint

Common Mistakes

Moving slow pointer two steps instead of one.

Using incorrect pointer member like prev or data.

To move the slow pointer one step forward, we use slow = slow->next;.

3fill in blank

hard

Fix the error in the while loop condition to correctly check if fast and fast->next are not NULL.

DSA C

while (fast != NULL && fast[1] != NULL) {

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A->prev

B->next->next

C->next

D->data

Attempts:

3 left

💡 Hint

Common Mistakes

Checking fast->prev which may not exist in singly linked list.

Checking fast->data which is not a pointer.

The condition should check fast->next != NULL to avoid accessing NULL pointer.

4fill in blank

hard

Fill both blanks to move fast pointer two steps and slow pointer one step inside the loop.

DSA C

fast = fast[1];
slow = slow[2];

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A->next->next

B->next

C->prev

D->data

Attempts:

3 left

💡 Hint

Common Mistakes

Moving fast pointer only one step.

Moving slow pointer two steps.

Using incorrect pointer members.

Inside the loop, fast moves two steps using fast->next->next, and slow moves one step using slow->next.

5fill in blank

hard

Fill all three blanks to print the middle element's data after finding it.

DSA C

printf("Middle element is %[1]\n", slow[2]); return [3];

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Ad

B->data

C0

Ds

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong format specifier like %s.

Not accessing the data field correctly.

Returning wrong value.

Use %d to print an integer, access the data with slow->data, and return 0 to indicate success.