problem:Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 先合并两个list,再根据归并排序的方法递归合并.假设总共有k个list,每个list的最大长度是n,那么运行时间满足递推式T(k) = 2T(k/2)+O(n*k).根据主定理,可以算出算法的总复杂度是O(nklogk).空间复杂度的话是递归栈的大小O(logk). /** * De…

题目 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 分析 合并k个有序链表. 我们从数据结构的链表章节学会了如何合并两个链表,针对此题,一个简单的解法便是遍历k次,两个链表合并,合并后的结果与下一个链表合并: 此时时间复杂度为O(nk),遗憾,提交会出现TLE. 所以,必须另觅他法,我们知道排序领域中很多方法都可以提高性能比如合并排序性能为O(n…

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…

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…

# -*- 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…

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 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 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…

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…

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…

一.题目说明 这个题目是23. Merge k Sorted Lists,归并k个有序列表生成一个列表.难度为Hard,实际上并不难,我一次提交就对了. 二.我的解答 就是k路归并,思路很简单,实现也不难. #include<iostream> #include<vector> using namespace std; struct ListNode { int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {}…

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 =…

LeetCode第21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. Example: Input: 1->2->4, 1->3->4 Output: 1->1->2->3->4->4 翻译: 合并两个有序链表并返回…

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 Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 两个方法: 方法1. 利用 STL 中的 multiset (根据结点内的值)自动对指针排序.空间 O(N), 时间 O(NlogN). (亦可用于 k 个无序链表).(AC: 164ms) /** * Definition for singly-linked…

leetcode-algorithms-23 Merge k Sorted Lists 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 解法…

堆是计算机科学中一类特殊的数据结构的统称.堆通常是一个可以被看做一棵树的数组对象.在队列中,调度程序反复提取队列中第一个作业并运行,因为实际情况中某些时间较短的任务将等待很长时间才能结束,或者某些不短小,但具有重要性的作业,同样应当具有优先权.堆即为解决此类问题设计的一种数据结构. 1 定义 n个元素序列{k1,k2...ki...kn},当且仅当满足下列关系时称之为堆:(ki <= k2i, ki <= k2i+1)或者(ki >= k2i, ki >= k2i+1), (i =…

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…

21.Merge Two Sorted Lists 初始化一个指针作为开头,然后返回这个指针的next class Solution { public: ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) { ListNode* dummy = ); ListNode* p = dummy; while(l1 && l2){ if(l1->val <= l2->val){ p->next = l1; p = p-&…

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 这道题最简单的方法就是我们将K个链表中的所有数据都存进数组中,然后对数据进行…

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题解:最开始用了最naive的方法,每次在k个链表头中找出最小的元素,插入到新链表中.结果果断TLE了. 分析一下,如果这样做,每取出一个节点,要遍历k个链表一次,假设k个链表一共有n个节点,那么就需要O(nk)的时间复杂度. 参考网上的代码,找到了用最小堆的方法.维护一个大小为k的最小堆,存放当前k…

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…

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…

题目链接 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 合并k个有序的链表,我们假设每个链表的平均长度是n.这一题需要用到合并两个有序的链表子过程 算法1: 最傻的做法就是先1.2合并,12结果和3合并,123结果和4合并,…,123..k-1结果和k合并,我们计算一下复杂度. 1.2合并,遍历2n个节点 12结果和3合并,遍历3n个节点 123…

1 题目 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 2 思路 当时看到这个题目就想到的是归并排序.好吧,但是,具体代码写不出来.题目给的是数组:public ListNode mergeKLists(ListNode[] lists),我就想,怎么归并排序,然后返回一个已经排好的,再进行递归.想破脑袋没想出来. 原来,可以赋值给一个Array…

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…

一天一道LeetCode系列 (一)题目 Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. (二)解题 合并K个已拍好序的链表.剑指上有合并两个已排好序的链表的算法,那么K个数,我们可以采用归并排序的思想,不过合并函数可能需要修改一下,换成合并两个已排好序的链表的方法.代码如下: /** * Definition for singly-linked…

转载:https://leetcode.windliang.cc/leetCode-23-Merge-k-Sorted-Lists.html 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…