63 lines
1.2 KiB
C++
63 lines
1.2 KiB
C++
#include <iostream>
|
|
|
|
/**
|
|
* Definition for singly-linked list.
|
|
*/
|
|
|
|
struct ListNode {
|
|
int val;
|
|
ListNode* next;
|
|
|
|
explicit ListNode(int x = 0, ListNode* next = nullptr) : val(x), next(next) {}
|
|
};
|
|
|
|
ListNode* construct(int x) {
|
|
return new ListNode(x);
|
|
}
|
|
|
|
template<typename... Ts>
|
|
ListNode* construct(int x, Ts... xs) {
|
|
return new ListNode(x, construct(xs...));
|
|
}
|
|
|
|
/**
|
|
* 61. Rotate List
|
|
* Given the head of a linked list, rotate the list to the right by k places.
|
|
*/
|
|
|
|
class Solution {
|
|
public:
|
|
static ListNode* rotateRight(ListNode* head, int k) {
|
|
if (!head || !head->next)
|
|
return head;
|
|
|
|
int n = 0;
|
|
for (auto* ptr = head; ptr; ptr = ptr->next)
|
|
++n;
|
|
int adv = (n - (k % n)) % n;
|
|
|
|
auto* ptr = head;
|
|
for (int i = 0; i < adv; ++i)
|
|
ptr = ptr->next;
|
|
auto* ptr2 = ptr;
|
|
while (ptr2->next)
|
|
ptr2 = ptr2->next;
|
|
ptr2->next = head;
|
|
for (auto* ptr3 = head;; ptr3 = ptr3->next) {
|
|
if (ptr3->next == ptr) {
|
|
ptr3->next = nullptr;
|
|
break;
|
|
}
|
|
}
|
|
return ptr;
|
|
}
|
|
};
|
|
|
|
int main() {
|
|
auto* head = construct(1,2);
|
|
head = Solution::rotateRight(head, 0);
|
|
for (auto* ptr = head; ptr; ptr = ptr->next)
|
|
std::cout << ptr->val << " ";
|
|
return 0;
|
|
}
|