leetcode 92. Reverse Linked List II

class Solution {
public:
ListNode* reverseBetween(ListNode* head, int m, int n)
{
ListNode *DummyHead{ new ListNode(0) };
DummyHead->next = head;
ListNode *p1 = DummyHead, *p2;
for (int i = 1; i < m; i++)
{
p1 = p1->next;
}
p2 = p1->next;
for (int i = 0; i < n - m; i++)
{
ListNode *temp = p2->next;
p2->next = temp->next;
temp->next = p1->next;
p1->next = temp;
}
return DummyHead->next;
}
};