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…

给定一个未排序的整数数组,找出最长连续序列的长度. 要求算法的时间复杂度为 O(n). 示例: 输入: [100, 4, 200, 1, 3, 2] 输出: 4 解释: 最长连续序列是 [1, 2, 3, 4].它的长度为 4. 如果不要求算法的时间复杂度为 O(n),排序后遍历即可.沒想出怎么解,看了思路后AC如下,主要是用到Hash映射 public class LongestConsecutiveSequence { public int longestConsecutive(int[]…

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…

最长连续序列 给定一个未排序的整数数组,找出最长连续序列的长度. 说明 要求你的算法复杂度为O(n) 样例 给出数组[100, 4, 200, 1, 3, 2],这个最长的连续序列是 [1, 2, 3, 4],返回所求长度 4 解题 排序后比较简单,快排O(nlogn) 后面只需要O(n)的时间复杂度求解了 发现原数组里面有重复数字的时候,下面方法行不通了. public class Solution { /** * @param nums: A list of integers * @retu…

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…

题目 给定一个未排序的整数数组,找出最长连续序列的长度. 要求算法的时间复杂度为O(n). 示例: 输入:[100, 4, 200, 1, 3, 2] 输出:4 解释:最长连续序列是[1, 2, 3, 4].它的长度为4 思路 思路一 先由小到大进行排序 考虑三种情况: 前后相差1,则是连续序列 前后相等,循环continue 最后一个元素,break 代码 def longestConsecutive(nums) -> int:     if nums:         nums.sort()…

124-最长连续序列 给定一个未排序的整数数组,找出最长连续序列的长度. 说明 要求你的算法复杂度为O(n) 样例 给出数组[100, 4, 200, 1, 3, 2],这个最长的连续序列是 [1, 2, 3, 4],返回所求长度 4 标签 数组 思路 由于限定了时间复杂度为 O(n),所以采取先排序再遍历的方式是不适合的,于是以空间换时间,用 set 存储 num 中的数字,方便检测 num 中某个数字是否存在,思路如下: 遍历 num 数组中的每个数字,如果其在 set 中存在,那么将其移除…