# -*- 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…
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…
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题解: 归并思想. Solution 1 /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {…
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…
合并K个有序链表,并且作为一个有序链表的形式返回.分析并描述它的复杂度. 详见:https://leetcode.com/problems/merge-k-sorted-lists/description/ 实现语言:Java /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ cla…
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.   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…