LeetCode61RotateList.java

classSolution {
publicListNoderotateRight(ListNodehead, intk) {
if(head == null || head.next == null || k == 0){
returnhead;
 }

// calculate the length of the linked list 
ListNodecurr = head;
intl = 1;
while(curr.next != null){
l++;
curr = curr.next;
 }

//after calculating the length, the current node will be at last node and pointing to null
// therefore point the last node(curr) to the head and make a cycle
curr.next = head;

//in the question k may be a large number and we will be just rotating in the cycle 
//therefore to avoid the repeatition we will take the modulo value
k = k % l;

//rotation

//take the remaining length
l = l - k;

//move the curr node to the last node of the rotated list
while(l > 0){
curr = curr.next;
l--;
 }
//now the next node will become the head of the new rotated list
head = curr.next;

//and since curr node is last, the next will become null
curr.next = null;

//finally just return the head
returnhead;
 }
}