CODE 41: Reverse Linked List II

Reverse a linked list from position m to n. Do it in-place and in one-pass.

For example:
Given 1->2->3->4->5->NULL, m = 2 and n = 4,

return 1->4->3->2->5->NULL.

Note:
Given m, n satisfy the following condition:
1 ≤ m ≤ n ≤ length of list.

public ListNode reverseBetween(ListNode head, int m, int n) {// IMPORTANT: Please reset any member data you declared, as// the same Solution instance will be reused for each test case.ListNode tmpHead = head;Stack<Integer> stack = new Stack<Integer>();int number = 1;if (tmpHead != null) {while (tmpHead != null && number < m) {tmpHead = tmpHead.next;number++;}ListNode tmp = tmpHead;while (tmp != null && number <= n) {stack.push(tmp.val);tmp = tmp.next;number++;}if (number > n) {while (!stack.isEmpty()) {tmpHead.val = stack.pop();tmpHead = tmpHead.next;}}}return head;}