- 1Singly Linked List Introduction
- 2Singly Linked List – Create Operation
- 3Singly Linked List – Insert Operation
- 4Singly Linked List – Delete Operation
- 5Singly Linked List – Traversal Operation
- 6Singly Linked List – Search Operation
- 7Singly Linked List – Get Length Operation
- 8Singly Linked List – Reverse Operation
- 9Doubly Linked List Introduction
- 10Doubly Linked List – Create Operation
- 11Doubly Linked List – Insert Operation
- 12Doubly Linked List – Delete Operation
- 13Doubly Linked List – Traversal Operation
- 14Doubly Linked List – Search Operation
- 15Doubly Linked List – Get Length Operation
- 16Doubly Linked List – Reverse Operation
Singly Linked List – Get Length Operation
Get Length Operation in Singly Linked List
Calculating the number of nodes in a singly linked list.
To get the length of a singly linked list, we traverse the list from the head and count each node until we reach the end of the list (null).
This operation does not require random access or indexing; we simply move forward using the next pointers while incrementing a counter.
Visual Example
Suppose we have a singly linked list with the following values:
We want to calculate the length of the list by traversing it node by node and counting.
Step-by-Step Length Calculation
- Start at the head node (value
5), count = 1. - Move to node with value
15, count = 2. - Move to node with value
25, count = 3. - Move to node with value
35, count = 4. - Move to node with value
45, count = 5.
We reach the end of the list. Total count = 5. This is the length of the singly linked list.
Complete Pseudocode: Get Length of Singly Linked List
This pseudocode shows how to calculate the length of a singly linked list by traversing it from start to end and counting the nodes.
function getLength(head):
curr = head
length = 0
while curr != null:
length += 1
curr = curr.next
return lengthLet’s understand each part of the code step by step.
function getLength(head):
curr = head
length = 0Explanation: We define the function and initialize two variables — curr to traverse the list and length to count nodes.
while curr != null:
length += 1
curr = curr.nextExplanation: We loop through the list, incrementing length for every node we visit and moving curr forward.
return lengthExplanation: Once the loop finishes (i.e., we've visited every node), we return the total length of the list.
Singly Linked List Get Length Operation Examples
The following examples demonstrate how to calculate the length of a singly linked list.
| Initial List | Length | Explanation |
|---|---|---|
| [10, 20, 30, 40, 50] | 5 | Start from the head and count each node until reaching null. |
| [5, 15, 25] | 3 | Three nodes are present in the list. Traverse and increment count by one for each. |
| [1] | 1 | Single node present. Length is 1. |
| [] | 0 | List is empty. Head is null, so the length is 0. |
Time Complexity of Singly Linked List Get Length Operation
| Length Calculation Case | Time Complexity | Explanation |
|---|---|---|
| Empty List | O(1) | We immediately check if the head is null and return 0. |
| Non-Empty List | O(n) | We traverse each node once from head to tail to count the total number of nodes. |
Space Complexity of Singly Linked List Get Length Operation
| Length Calculation | Space Complexity | Explanation |
|---|---|---|
| Get Length | O(1) | We use a single counter and a pointer variable to traverse the list. No additional space is required, regardless of the list size. |
Key Takeaways
- The length of a singly linked list is calculated by traversing the list from head to tail.
- Each node is visited exactly once, making the operation linear in time.
- Only one pointer and one counter are needed, so space complexity remains constant.
- This operation does not modify the list structure — it’s a read-only traversal.
- Useful when the list does not maintain a length property and dynamic size checks are required.
Sign in with Google
Comments
Loading comments...