数据结构算法 -- 翻转链表

目录

翻转链表

翻转链表中第m个节点到第n个节点的部分
m，n满足1 ≤ m ≤ n ≤ 链表长度

样例 1：

输入: 1->2->3->4->5->NULL, m = 2 and n = 4,
输出: 1->4->3->2->5->NULL.

样例 2：

输入: 1->2->3->4->NULL, m = 2 and n = 3,
输出: 1->3->2->4->NULL.

import java.util.Stack; /**
 * Definition for ListNode
 * public class ListNode {
 * int val;
 * ListNode next;
 * ListNode(int x) {
 * val = x;
 * next = null;
 * }
 * }
 */ public class Solution { /**
	 * @param head: ListNode head is the head of the linked list
	 * @param m:    An integer
	 * @param n:    An integer
	 * @return: The head of the reversed ListNode
	 */ public ListNode reverseBetween(ListNode head, int m, int n) { // write your code here if (n == m) { return head; } ListNode mNode = head; ListNode tempH = head; int i = 1; while (i < m) { tempH = tempH.next; i++; mNode = tempH; } Stack<ListNode> stack = new Stack<>(); while (i < n) { tempH = tempH.next; i++; stack.push(tempH); } for (int j = 0; j <= (n - m) / 2; j++) { tempH = stack.pop(); int tempV = mNode.val; mNode.val = tempH.val; tempH.val = tempV; mNode = mNode.next; } return head; } } 

原题链接点这里