Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Your algorithm should run in O(n) complexity. Example: Input: [100, 4, 200, 1, 3, 2] Output: 4 Explanation: The longest consecutive elements sequence i…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example,Given[100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is[1, 2, 3, 4]. Return its length:4. Your algorithm should run in O(n…

转载请注明来自souldak,微博:@evagle 题目(来自leetcode): 给你一个n个数的乱序序列,O(N)找出其中最长的连续序列的长度. 例如给你[100, 4, 200, 1, 3, 2],那么最长的连续序列为[1, 2, 3, 4],所以返回4. 思路: 最简单直接的想法是:将数组排序,然后扫一遍排好序的序列,从中找出最长的即可,这样的话时间是O(nlogn)+O(n),显然不符合题目要求,会超时. 那怎么样不排序就能做出来呢? 我们先抛开算法,想想自己会怎么找,当数组很小,你可…

2018-11-25 16:28:09 问题描述: 问题求解: 方法一.如果不要求是线性时间的话,其实可以很直观的先排序在遍历一遍就可以得到答案,但是这里明确要求是O(n)的时间复杂度,那么就给了一个强烈的提示就是使用Hash来进行解决.方法一的思路很明确也很暴力,就是将所有的数字都保存到一个Hash表中,如果当前的数字是首个元素,那么就从他开始往后串连,得到以当前数字为首的最长连续序列,最后取max即可.时间复杂度是O(n),因为至多只会读取一个元素两次.…

Given a binary tree, find the length of the longest consecutive sequence path. The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The longest consecutive path need to be from p…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4, 200, 1, 3, 2], The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4. Your algorithm should run i…

Given a binary tree, you need to find the length of Longest Consecutive Path in Binary Tree. Especially, this path can be either increasing or decreasing. For example, [1,2,3,4] and [4,3,2,1] are both considered valid, but the path [1,2,4,3] is not v…

Given a binary tree, find the length of the longest consecutive sequence path. The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The longest consecutive path need to be from p…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Your algorithm should run in O(n) complexity. Example: Input: [100, 4, 200, 1, 3, 2] Output: 4 Explanation: The longest consecutive elements sequence i…

Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given [100, 4, 200, 1, 3, 2],The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4.Your algorithm should run in O(…