题解 | #链表内指定区间反转#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param head ListNode类 
     * @param m int整型 
     * @param n int整型 
     * @return ListNode类
     */
    public ListNode reverseBetween (ListNode head, int m, int n) {
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        ListNode g = dummy;
        ListNode p = head;
        for(int i = 0;i<m-1;i++){
            g = g.next;
            p = p.next;
        }
        for(int i = 0;i<n-m;i++){
            ListNode remove = p.next;
            p.next = p.next.next;
            remove.next = g.next;
            g.next = remove;
        }
        return dummy.next;
    }
}