1.题目描述: 2.解题思路: 本题是要合并两个已经有序的单链表,思路很简单,有两种方法:非递归和递归. 3.Java代码: (1)非递归: 为方便操作,定义一个辅助的头节点,然后比较原来两个链表的头节点,将小的那一个加入到合并链表,最后,当其中一个链表为空时,直接将另一个链表接入到合并链表即可. //public class LeetCode21 为测试 public class LeetCode21 { public static void main(String[] args) { Lis…

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 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. 题目意思很简单,就是合并两个有序链表,头需要是原先的两个链表中的一个.这道题在本科生的数据结构书上就有讲,原理就就是:两个链表A,B分别逐个遍历,判断两个元素的大小,取小的作为新链表的下一个节点.让小学生做,他们也能…

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. 思路:使用伪头部 class Solution { public: ListNode *mergeTwoLists(ListNode *l1, ListNode *l2) { ListNode fakehead();…

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 解题思路: 1.先取出k个list的首元素,每个首元素是对应list中的最小元素,组成一个具有k个结点的最小堆:o(k*logk) 2.此时堆顶元素就是所有k个list的最小元素,将其pop出,并用此最小元素所在list上的下一个结点(如果存在)填充堆顶,并执行下滤操作,重新构建堆.o(logk) 3…

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. 解题: 题目比较简单,注意由于表头不确定,因此新建一个结点指向新创建的链表: 解题步骤: 1.判断l1和l2是否有效 2.新建preHead结点,newlist指针指向preHead: 3.循环开始,满足l1和l2都…

1.题目描述: 2.解题思路: 题意:将K个已经排序的链表合并成一个排序的链表,分析并描述所用算法的复杂度. 方法一:基于“二分”思想的归并排序.本文用非递归和递归两种方法实现. (1)非递归:归并排序”(Merging Sort):将两个或两个以上的有序表组合成一个新的有序表,无论是顺序存储结构还是链式存储结构,对于任何两个长度分别为m和n的有序表,其组合都可在O(m+n)的时间复杂度量级上完成.对于K个有序表,假设共有N个元素,且这些有序表初始状态都不为空,每个有序表平均拥有N/K个元素.最…

这道题是LeetCode里的第21道题. 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. 示例: 输入:1->2->4, 1->3->4 输出:1->1->2->3->4->4 这道题需要考虑的地方挺多的,首先是头节点的处理,还有尾节点的链接问题.对于头节点,我的想法是先对 l1, l2 的值进行比较,然后把 l1 指向头节点值小的,这样保证了 l1 绝对小于等于 l2,也就是说头节点的链接问题…

思路:指针p用于串联怎个链表,比较两个指针的大小,连接较小的一个.如果一个链表到达链尾,连接另外一个链表余下来的所以节点. public ListNode mergeTwoLists(ListNode l1, ListNode l2) { ListNode head; ListNode p = null; //判断初始链表是否为空 if (l1 == null && l2 == null) { return null; } if(l1==null){ return l2; } if(l2=…

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…

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…

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 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 解决思路:最简单…

题目: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. struct ListNode { int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {} }; ListNode *mergeTwoL…

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…

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…

21. Merge Two Sorted Lists[easy] 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. 解法一: /** * Definition for singly-linked list. * struct ListNode { * int val…

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,有序链表,递归,迭代,题解,leetcode, 力扣,Python, C++, Java 目录 题目描述 题目大意 解题方法 迭代 Python解法 C++解法 Java解法 递归 日期 题目地址:https://leetcode.com/problems/merge-two-sorted-lists/ 题目描述 Merge two sorted…

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…

Given two sorted integer arrays A and B, merge B into A as one sorted array. Note: You may assume that A has enough space to hold additional elements from B. The number of elements initialized in A and B are m and n respectively. 思路: 归并的一部分,比Merge Tw…

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 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 (ascending) linked lists and return it as a new sorted list. The new sorted list should be made by splicing together the nodes of the two lists and sorted in ascending order. Have you met this question in a real interview? Yes Exampl…

问题: Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 官方难度: Hard 翻译: 合并k个已排序的链表,得到一个新的链表并且返回其第一个节点.分析并阐述其复杂度. 这是No.021(Merge Two Sorted Lists)的深入研究. 可以借鉴归并排序的思想,对于长度为k的数组,依次进行二路归并,返回这两个链表合并之后的头结点(利用No.…

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…

Merge Two Sorted Lists https://leetcode.com/problems/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. 算法思想: 连接两个排好序(假设升序,降序类似)的链表,这是一…

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…