Mergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题解: Merge k sorted linked list就是merge 2 sorted linked list的变形题。 而且我们很自然的就想到了经典的Merge Sort,只不过那个是对数组进行sort。而不同的地方,仅仅是Merge两个list的操作不同。 这里来...
Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 思路:合并k路有序链表,可以用最小堆,然后每次送入堆中,取出最小的,并将该链表下一值取出放入 1、使用优先级队列模拟小根堆 /** * Definition for singly-linked list. * struct ListNode { * int va...
Mergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题解: 是Merge Two Sorted Lists的进阶版,现在是k条,用divide and conquer, 两条两条合并 最后合并成一个大的。 Note: mergeSort中别忘了最后的返回值是lists[l]. 分析时间复杂度T(k) = 2T(k/2) +...
return mergeSort(lists, 0, n-1); } private ListNode mergeSort(ListNode[] lists, int L, int R){ if(L>R){ return null; } if(L==R){ return lists[L]; } int mid = L + (R-L)/2; ListNode left = mergeSort(lists, L, mid); ListNode right = mergeSort(lists, mid+1, R); ...
用一个大小为K的最小堆(用优先队列+自定义降序实现)(优先队列就是大顶堆,队头元素最大,自定义为降序后,就变成小顶堆,队头元素最小),先把K个链表的头结点放入堆中,每次取堆顶元素,然后将堆顶元素所在链表的下一个结点加入堆中。 代码语言:javascript ...
今天的笔记包含多路归并(K-way merge)与拓扑排序(Topological Sort)类型下的X个题目。其中“多路归并”在leetcode上的编号和题名分别是: 21 - 合并两个有序列表 23 - 合并k个排序列表 373 - 查找和最小的k对数字 378 - 有序矩阵中第k小的元素 而拓扑排序的练习包含以下两个部分: 排序的实现(LeetCode对应...
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Doing this for CSci 4041, after we've learned MergeSort. What I have for now: While it works, the runtime is 99ms. I'm expecting it's because I've used mergeTwoLists(which was made in 21.) n times, while each call cause a runtime of O(n), thus the total is O(n^2). ...
[]forlsinlists:ifnotls:# 千万小心input = [[]]或者input里存在[]这个空linked list的情况continuepool.append(ls.val)while(ls.next!=None):ls=ls.nextpool.append(ls.val)pool.sort()iflen(pool)==0:# case1:空returnNoneresult=ListNode(pool[0])# case2: 只有1个元素iflen(pool)==1:return...
(https://leetcode.com/subscribe/) for the access to premium questions.) ## Algorithms * [Bit Manipulation](https://github.com/kamyu104/LeetCode#bit-manipulation) * [Array](https://github.com/kamyu104/LeetCode#array) * [String](https://github.com/kamyu104/LeetCode#string) * [Linked ...