题目:Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题意:把k个排序成一个有序链表. 用优先队列先把k个链表遍历一遍把值存起来,在建一个新链表吧数从优先队列里一个个放进去,注意空指针的判断. /** * Definition for singly-linked list. * struct ListNode { * int val; * List…
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 这道混合插入有序链表和我之前那篇混合插入有序数组非常的相似Merge Sorted Array,仅仅是数据结构由数组换成了链表而已,代码写起来反而更简洁.具体思想就是新建一个链表,然后比较两个链表中的元素值,把较小的…
Merge Two Sorted Lists Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. Show Tags SOLUTION 1: 使用dummynode记录头节点的前一个,轻松完成,2分钟就AC啦! /** * Definition for singly-…
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 分析:思路比较简单,遍历两个有序链表,每次指向最小值. code如下: /** * Definition for singly-linked list. * struct ListNode { * int val;…
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 题意:合并两个排好的链表并返回新的链表. 可以使用归并排序,从两链表的表头,取出结点,比较两值,将较小的放在新链表中.如1->3->5->6和2->4->7->8,先将1放入新链表,然后将3…
# Definition for singly-linked list. # class ListNode(object): # def __init__(self, x): # self.val = x # self.next = None class Solution(object): def mergeTwoLists(self, l1, l2): """ :type l1: ListNode :type l2: ListNode :rtype: ListNode &q…
  题意: 将两个有序的链表归并为一个有序的链表. 思路: 设合并后的链表为head,现每次要往head中加入一个元素,该元素要么属于L1,要么属于L2,可想而知,此元素只能是L1或者L2的首个元素,那么进行一次比较就可以知道是谁了.操作到L1或L2其中一个已经没有元素为止,剩下的直接加到head后面. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListN…
21. 合并两个有序链表 21. Merge Two Sorted Lists 题目描述 将两个有序链表合并为一个新的有序链表并返回.新链表是通过拼接给定的两个链表的所有节点组成的. LeetCode21. Merge Two Sorted Lists 示例: 输入: 1->2->4, 1->3->4 输出: 1->1->2->3->4->4 Java 实现 ListNode 类 class ListNode { int val; ListNode n…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 这道题让我们合并k个有序链表,之前我们做过一道Merge Two Sorted Lists 混合插入有序链表,是混合插入两个有序链表.这道题增加了难度,变成合并k个有序链表了,但是不管合并几个,基本还是要两两合并.那么我们首先考虑的方法是能不能利用之前那道题的解法来解答此题.答案是肯定的,但是需要修改…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example: Input: [   1->4->5,   1->3->4,   2->6 ] Output: 1->1->2->3->4->4->5->6 这道题让我们合并k个有序链表,最终合并出来的结果也必须是有序的,之前做过一道 M…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 解题思路一: 之前我们有mergeTwoLists(ListNode l1, ListNode l2)方法,直接调用的话,需要k-1次调用,每次调用都需要产生一个ListNode[],空间开销很大.如果采用分治的思想,对相邻的两个ListNode进行mergeTwoLists,每次将规模减少一半,直到…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 23: Merge k Sorted Listshttps://oj.leetcode.com/problems/merge-k-sorted-lists/ Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. ===Comments…
1. Merge Two Sorted Lists 题目链接 题目要求:  Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 这道题目题意是要将两个有序的链表合并为一个有序链表.为了编程方便,在程序中引入dummy节点.具体程序如下: /** * Definitio…
题目 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 翻译 合并k个有序的链表 Hints Related Topics: LinkedList, Divide and Conquer, Heap Solution1:Divide and Conquer 参考 归并排序-维基百科 思路:分治,先分成两个子任务,然后递归子任务,最后回溯回来..这里就…
Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Show Tags 参考资料: http://blog.csdn.net/linhuanmars/article/details/19899259. SOLUTION 1: 使用分治法.左右分别递归调用Merge K sorted List,然后再使用merg…
题目链接: https://leetcode.com/problems/merge-k-sorted-lists/?tab=Description Problem: 给出k个有序的list, 将其进行合并得到一个有序的list   对于给出的ListNode[] lists ,可以进行两两合并.divide and conquer  将list分为前后两部分,对前半部分再次进行分半操作,对后半部分进行分半操作,然后将其进行合并操作. 合并操作也就是对两个list进行合并 合并操作可以采用递归算法…
23. 合并K个排序链表 23. Merge k Sorted Lists 题目描述 合并 k 个排序链表,返回合并后的排序链表.请分析和描述算法的复杂度. LeetCode23. Merge k Sorted Lists困难 示例: 输入: [   1->4->5,   1->3->4,   2->6] 输出: 1->1->2->3->4->4->5->6 Java 实现 public class ListNode { int va…
作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 个人公众号:负雪明烛 本文关键词:合并,链表,单链表,题解,leetcode, 力扣,Python, C++, Java 题目地址: https://leetcode.com/problems/merge-k-sorted-lists/description/ 题目描述: Merge k sorted linked lists and return it as one sorted li…
Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.   采用优先队列priority_queue 把ListNode放入优先队列中,弹出最小指后,如果该ListNode有下一个元素,则把下一个元素放入到队列中     /** * Definition for singly-linked list. * stru…
Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题目意思: 合并K条已经排序的链表.分析时间复杂度. 解题思路: 很容易就想起之前学的合并两条链表的算法,这一题其实就是那个题目的扩展,变成合并K条了.我采用的方法就是迭代法. 如果只有一条,直接返回.如果只有两条,就只需要调用mergeTwo一下.如果超过两…
Merge Two Sorted Lists Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 依次拼接 复杂度 时间 O(N) 空间 O(1) 思路 该题就是简单的把两个链表的节点拼接起来,我们可以用一个Dummy头,将比较过后的节点接在这个Dummy头之后.最后…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 思路:这题最容易想到的是,(假设有k个链表)链表1.2合并,然后其结果12和3合并,以此类推,最后是123--k-1和k合并.至于两链表合并的过程见merge two sorted lists的分析.复杂度的分析见JustDoIT的博客.算法复杂度:假设每个链表的平均长度是n,则1.2合并,遍历2n个…
这两天一直也没有顾上记录一下自己做过的题目,回头看看,感觉忘的好快,今天做了一个hard,刚开始觉得挺难得,想了两种方法,一种是每次都从k个list中选取最小的一个,为空的直接跳过,再就是每次合并其中的两个list,直到最终合并完成,这就要用到地柜的方法,还有就是划分,感觉递归的思路比较清晰,就拿地柜的写了,使用递归的方法,这道题目就是以21. Merge Two Sorted Lists  为基础的. 阶梯思路就是,每次都从中间切割lists,直到切割完之后左侧或者右侧为,一个或者两个list…
描述 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example: Input: [   1->4->5,   1->3->4,   2->6 ] Output: 1->1->2->3->4->4->5->6 思路 借鉴Merge Two Sorted Lists的解决思路,对两个数…
题目要求:Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Analysis The simplest solution is using PriorityQueue. The elements of the priority queue are ordered according to their natu…
Question 23. Merge k Sorted Lists Solution 题目大意:合并链表数组(每个链表中的元素是有序的),要求合并后的链表也是有序的 思路:遍历链表数组,每次取最小节点 Java实现: public ListNode mergeKLists(ListNode[] lists) { ListNode preHead = new ListNode(0); ListNode minNode = getMinNode(lists); ListNode tmpNode =…
乘风破浪:LeetCode真题_023_Merge k Sorted Lists 一.前言 上次我们学过了合并两个链表,这次我们要合并N个链表要怎么做呢,最先想到的就是转换成2个链表合并的问题,然后解决,再优化一点的,就是两个两个合并,当然我们也可以一次性比较所有的元素,然后一点点的进行合并等等. 二.Merge k Sorted Lists 2.1 问题 2.2 分析与解决 首先我们看看官方的解法: 第一种方法:暴力算法,将所有的元素放到一个数组里面,排序之后再用指针链接. # Definit…
1. Merge Two Sorted Lists 我们先来看这个 问题: Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 是的,这是一个非常简单链表操作问题.也许你只需要花几分种便能轻松写出代码. 2. Merge k Sorted Lists 我们现在来研究这…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 1,类似于Merge Sort的方法做k-1次,每次合并两个,但是这种方法超时. for(int i = 1; i < lists.size(); i++) head = merge(head, lists[i]); 2,分治法,合并的时间复杂度O(logN),不用递归,空间复杂度O(1) 思想很简单…
Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. Example: Input: 1->2->4, 1->3->4 Output: 1->1->2->3->4->4 这道混合插入有序链表和我之前那篇混合插入有序数组非常的相…