Do linked lists have a length?

Length of a Linked List in Python

Suppose we have a singly linked list, we have to find its length. The linked list has fields next and val.

So, if the input is like [2 -> 4 -> 5 -> 7 -> 8 -> 9 -> 3], then the output will be 7.

To solve this, we will follow these steps

• count := 0
• while node is non null, do
  • count := count + 1
  • node:= next of node
• return count

Let us see the following implementation to get better understanding

Example

Live Demo

class ListNode: def __init__[self, data, next = None]: self.val = data self.next = next def make_list[elements]: head = ListNode[elements[0]] for element in elements[1:]: ptr = head while ptr.next: ptr = ptr.next ptr.next = ListNode[element] return head class Solution: def solve[self, node]: count = 0 while node: count +=1 node=node.next return count ob = Solution[] head = make_list[[2,4,5,7,8,9,3]] print[ob.solve[head]]

Input

[2,4,5,7,8,9,3]

Output

7