Delete Node by Value in DSA C - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the first step when deleting a node by value in a singly linked list?

Start from the head node and check if the head itself contains the value to delete.

beginner

How do you handle deleting a node that is not the head in a singly linked list?

Traverse the list to find the node just before the target node, then change its next pointer to skip the target node.

beginner

Why do we need to keep track of the previous node when deleting a node by value?

Because we need to update the previous node's next pointer to bypass the node being deleted.

beginner

What should you do if the value to delete is not found in the linked list?

Do nothing or return the original list unchanged, since the value does not exist.

intermediate

What happens to the memory of the deleted node in C after deletion?

You should free the memory of the deleted node using free() to avoid memory leaks.

In a singly linked list, which pointer do you update to delete a node that is not the head?

A The previous node's next pointer

B The deleted node's next pointer

C The head pointer

D The tail pointer

To remove a node, you update the previous node's next pointer to skip the node being deleted.

What should you do if the node to delete is the head node?

A Do nothing

B Update the tail pointer

C Delete the entire list

D Update the head pointer to the next node

If the head node contains the value, update the head pointer to point to the next node.

What is the time complexity of deleting a node by value in a singly linked list?

A O(1)

B O(n)

C O(log n)

D O(n^2)

You may need to traverse the entire list to find the node, so the time complexity is O(n).

What happens if you forget to free the deleted node's memory in C?

A Memory leak occurs

B Program crashes immediately

C Node is automatically freed

D Nothing happens

Not freeing memory causes memory leaks, which waste system resources.

If the value to delete is not found, what should the function return?

A A new empty list

B NULL

C The original head pointer

D An error code

If the value is not found, return the original list unchanged.

Explain step-by-step how to delete a node by value in a singly linked list.

Think about how pointers change and memory management.

What are the edge cases to consider when deleting a node by value in a linked list?

Consider where the node is and if the list is empty.