Given the head of a linked list, rotate the list to the right by k places.
Example 1:
Input: head = [1,2,3,4,5], k = 2 Output: [4,5,1,2,3]
Example 2:
Input: head = [0,1,2], k = 4 Output: [2,0,1]
Constraints:
- The number of nodes in the list is in the range
[0, 500]. -100 <= Node.val <= 1000 <= k <= 2 * 109
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def rotateRight(self, head: ListNode, k: int) -> ListNode:
if k == 0 or head is None or head.next is None:
return head
n, cur = 0, head
while cur:
n, cur = n + 1, cur.next
k %= n
if k == 0:
return head
slow = fast = head
for _ in range(k):
fast = fast.next
while fast.next:
slow, fast = slow.next, fast.next
start = slow.next
slow.next = None
fast.next = head
return start/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode rotateRight(ListNode head, int k) {
if (k == 0 || head == null || head.next == null) {
return head;
}
int n = 0;
for (ListNode cur = head; cur != null; cur = cur.next) {
++n;
}
k %= n;
if (k == 0) {
return head;
}
ListNode slow = head, fast = head;
while (k-- > 0) {
fast = fast.next;
}
while (fast.next != null) {
slow = slow.next;
fast = fast.next;
}
ListNode start = slow.next;
slow.next = null;
fast.next = head;
return start;
}
}/**
* Definition for singly-linked list.
* class ListNode {
* val: number
* next: ListNode | null
* constructor(val?: number, next?: ListNode | null) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
* }
*/
function rotateRight(head: ListNode | null, k: number): ListNode | null {
if (k == 0 || head == null || head.next == null) return head;
// mod n
let n = 0;
let p = head;
while (p != null) {
++n;
p = p.next;
}
k %= n;
if (k == 0) return head;
let fast = head,
slow = head;
for (let i = 0; i < k; ++i) {
fast = fast.next;
}
while (fast.next != null) {
slow = slow.next;
fast = fast.next;
}
let start = slow.next;
slow.next = null;
fast.next = head;
return start;
}/**
* Definition for singly-linked list.
* class ListNode {
* val: number
* next: ListNode | null
* constructor(val?: number, next?: ListNode | null) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
* }
*/
function rotateRight(head: ListNode | null, k: number): ListNode | null {
if (head == null || k === 0) {
return head;
}
let n = 0;
let cur = head;
while (cur != null) {
cur = cur.next;
n++;
}
k = k % n;
if (k === 0) {
return head;
}
cur = head;
for (let i = 0; i < n - k - 1; i++) {
cur = cur.next;
}
const res = cur.next;
cur.next = null;
cur = res;
while (cur.next != null) {
cur = cur.next;
}
cur.next = head;
return res;
}/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* rotateRight(ListNode* head, int k) {
if (k == 0 || !head || !head->next) {
return head;
}
int n = 0;
for (ListNode* cur = head; !!cur; cur = cur->next) {
++n;
}
k %= n;
if (k == 0) {
return head;
}
ListNode *slow = head, *fast = head;
while (k-- > 0) {
fast = fast->next;
}
while (fast->next) {
slow = slow->next;
fast = fast->next;
}
ListNode* start = slow->next;
slow->next = nullptr;
fast->next = head;
return start;
}
};/**
* Definition for singly-linked list.
* public class ListNode {
* public int val;
* public ListNode next;
* public ListNode(int val=0, ListNode next=null) {
* this.val = val;
* this.next = next;
* }
* }
*/
public class Solution {
public ListNode RotateRight(ListNode head, int k) {
if (k == 0 || head == null || head.next == null)
{
return head;
}
var n = 0;
for (ListNode cur = head; cur != null; cur = cur.next)
{
++n;
}
k %= n;
if (k == 0)
{
return head;
}
ListNode slow = head, fast = head;
while (k-- > 0)
{
fast = fast.next;
}
while (fast.next != null)
{
slow = slow.next;
fast = fast.next;
}
ListNode start = slow.next;
slow.next = null;
fast.next = head;
return start;
}
}// Definition for singly-linked list.
// #[derive(PartialEq, Eq, Clone, Debug)]
// pub struct ListNode {
// pub val: i32,
// pub next: Option<Box<ListNode>>
// }
//
// impl ListNode {
// #[inline]
// fn new(val: i32) -> Self {
// ListNode {
// next: None,
// val
// }
// }
// }
impl Solution {
pub fn rotate_right(mut head: Option<Box<ListNode>>, mut k: i32) -> Option<Box<ListNode>> {
if head.is_none() || k == 0 {
return head;
}
let n = {
let mut cur = &head;
let mut res = 0;
while cur.is_some() {
cur = &cur.as_ref().unwrap().next;
res += 1;
}
res
};
k = k % n;
if k == 0 {
return head;
}
let mut cur = &mut head;
for _ in 0..n - k - 1 {
cur = &mut cur.as_mut().unwrap().next;
}
let mut res = cur.as_mut().unwrap().next.take();
cur = &mut res;
while cur.is_some() {
cur = &mut cur.as_mut().unwrap().next;
}
*cur = head.take();
res
}
}