zoukankan      html  css  js  c++  java
  • *Odd Even Linked List

    Given a singly linked list, group all odd nodes together followed by the even nodes. Please note here we are talking about the node number and not the value in the nodes.

    You should try to do it in place. The program should run in O(1) space complexity and O(nodes) time complexity.

    Example:
    Given 1->2->3->4->5->NULL,
    return 1->3->5->2->4->NULL.

    Note:
    The relative order inside both the even and odd groups should remain as it was in the input. 
    The first node is considered odd, the second node even and so on ...

    Credits:
    Special thanks to @DjangoUnchained for adding this problem and creating all test cases.

    解法:

    O(N) time, O(1), space 

    /**
     * Definition for singly-linked list.
     * public class ListNode {
     *     int val;
     *     ListNode next;
     *     ListNode(int x) { val = x; }
     * }
     */
    public class Solution {
    public ListNode oddEvenList(ListNode head) {
        if (head != null) {
        
            ListNode odd = head, even = head.next, evenHead = even; 
        
            while (even != null && even.next != null) {
                odd.next = odd.next.next; 
                even.next = even.next.next; 
                odd = odd.next;
                even = even.next;
            }
            odd.next = evenHead; 
        }
        return head;
    }}

    reference:

    https://discuss.leetcode.com/topic/34292/simple-o-n-time-o-1-space-java-solution

  • 相关阅读:
    HBase 安装设置
    Python中通过函数对象创建全局变量
    Scala 中 构造函数,重载函数的执行顺序
    Hive 安装配置
    976. 三角形的最大周长
    922. 按奇偶排序数组 II
    350. 两个数组的交集 II
    349. 两个数组的交集
    242. 有效的字母异位词
    925. 长按键入
  • 原文地址:https://www.cnblogs.com/hygeia/p/5775460.html
Copyright © 2011-2022 走看看