Count Linked List Nodes

Problem

Given a singly linked list. The task is to find the length of the linked list, where length is defined as the number of nodes in the linked list.

Examples:

Example 1:

Input:
LinkedList: 1->2->3->4->5
Output: 5
Explanation: Count of nodes in the linked list is 5, which is its length.

Example 2:

Input:
LinkedList: 2->4->6->7->5->1->0
Output: 7
Explanation: Count of nodes in the linked list is 7. Hence, the output is 7.

Your task:

Your task is to complete the given function getCount(), which takes a head reference as an argument and should return the length of the linked list.

• Expected Time Complexity: $O(N)$
• Expected Auxiliary Space: $O(1)$

Constraints:

• $1<=N<=10^5$
• $1<=value<=10^3$

Solution

Python

def getCount(self, head_node):
    temp = head_node
    count = 0
    while temp is not None:
        count+=1
        temp = temp.next
    return count

Java

public static int getCount(Node head) {
    Node temp = head;
    int count = 0;
    while(temp!=null) {
        count++;
        temp = temp.next;
    }
    return count;
}

C++

int getCount(struct Node* head){
    struct Node* temp = head;
    int count = 0;
    while (temp != NULL) {
        count++;
        temp = temp->next;
    }
    return count;
}

C

int getCount(struct Node* head) {
    struct Node* temp = head;
    int count = 0;
    while (temp != NULL) {
        count++;
        temp = temp->next;
    }
    return count;
}

• Time Complexity: $O(N)$
• Auxiliary Space: $O(1)$