Given a linklist, task is to make a function which check whether the length of linklist is even or odd.

Examples:

Input :1->2->3->4->NULLOutput :EvenInput :1->2->3->4->5->NULLOutput :Odd

**Method 1: Count the codes linearly**

Traverse the entire Linked List and keep counting the number of nodes. As soon as the loop is finished, we can check if the count is even or odd. You may try it yourself.

**Method 2: Stepping 2 nodes at a time**

**Approach:**

1. Take a pointer and move that pointer two nodes at a time 2. At the end, if the pointer is NULL then length is Even, else Odd.

// C program to check length // of a given linklist #include<stdio.h> #include<stdlib.h> // Defining structure struct Node { int data; struct Node* next; }; // Function to check the length of linklist int LinkedListLength(struct Node* head) { while (head && head->next) { head = head->next->next; } if (!head) return 0; return 1; } // Push function void push(struct Node** head, int info) { // Allocating node struct Node* node = (struct Node*) malloc(sizeof(struct Node)); // Info into node node->data = info; // Next of new node to head node->next = (*head); // head points to new node (*head) = node; } // Driver function int main(void) { struct Node* head = NULL; // Adding elements to Linked List push(&head, 4); push(&head, 5); push(&head, 7); push(&head, 2); push(&head, 9); push(&head, 6); push(&head, 1); push(&head, 2); push(&head, 0); push(&head, 5); push(&head, 5); int check = LinkedListLength(head); // Checking for length of // linklist if(check == 0) { printf("Even\n"); } else { printf("Odd\n"); } return 0; }

Output:

Odd

**Time Complexity:** O(n)

**Space Complexity:** O(1)

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