Can you rotate a Linked List by k places?

Given a linked list, rotate the list to the right by k places.

// example 1
Input: 1->2->3->4->5->NULL, k = 2
Output: 4->5->1->2->3->NULL
Explanation:
rotate 1 steps to the right: 5->1->2->3->4->NULL
rotate 2 steps to the right: 4->5->1->2->3->NULL

// example 2
Input: 0->1->2->NULL, k = 4
Output: 2->0->1->NULL
Explanation:
rotate 1 steps to the right: 2->0->1->NULL
rotate 2 steps to the right: 1->2->0->NULL
rotate 3 steps to the right: 0->1->2->NULL
rotate 4 steps to the right: 2->0->1->NULL

Here’s the solution:

    public ListNode rotateRight(ListNode head, int k) {
        
        if(head == null || k == 0){
            return head;
        }
 
        int len = 0;   
        ListNode temp = head;
        
        // get the list length
        while(temp != null){
            temp = temp.next;
            len++;
        }
        
        // make sure rotating steps not exceeding list length
        k = k % len; 
        
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        head = dummy; 
        ListNode tail = dummy;
    
        // move k steps from head
        for(int i = 0; i < k; i++){
            head = head.next;
        }
        
        // move both head and tail forward until last node is reached
        while(head.next != null){
            head = head.next; 
            tail = tail.next;    
        }
        
        // connect the nodes
        head.next = dummy.next;
        dummy.next = tail.next;
        tail.next = null;
        
        return dummy.next;             
    }
 

Here’s some visual graphs for better understanding.

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With the aid of visual graphic, is it better to understand linked list operation now? Hope you enjoy this post! See ya!