[leetcode]Reverse Linked List II

Again, use example diagram to think of the solution.

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public class Solution { public ListNode reverseBetween(ListNode head, int m, int n) { ListNode dummy = new ListNode(-1); dummy.next = head; ListNode previous = dummy; ListNode current = head; for (int i = 1; i < m; i++){ previous = current; current = current.next; } ListNode front = previous; ListNode tail = current; previous = current; current = current.next; for (int i = m; i < n; i++){ ListNode next = current.next; current.next = previous; previous = current; current = next; } front.next = previous; tail.next = current; return dummy.next; } }