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…

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…

前言: 每道题附带动态示意图,提供java.python两种语言答案,力求提供leetcode最优解. 描述: 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: 首先,我们先来看一个简单的例子:序列123 序列 56,插入4,求连续序列长度. 很容易得出结论,答案是6,那么这个6是怎么来的呢?6 = len(1,2…

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…

128. 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. 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. class Solution { public int longestConsecutive(int[] nums) { Set<Integer> numsSet = new HashSet<>(); for (Integer nu…

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…

原题地址 1. 把所有元素都塞到集合里2. 遍历所有元素,对于每个元素,如果集合里没有,就算了,如果有的话,就向左向右拓展,找到最长的连续范围,同时在每次找的时候都把找到的删掉.这样做保证了同样的连续序列只会被遍历一次,从而保证时间复杂度. 时间复杂度O(n) 代码: int longestConsecutive(vector<int> &num) { set<int> record; ; for (auto n : num) record.insert(n); while…

Problem: Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that: Only one letter can be changed at a time Each intermediate word must exist in the dictionary For example, Given:sta…

class Solution { public: int longestConsecutive(vector<int>& nums) { ; unordered_map<int,int> m; ;i < nums.size();i++){ if(m.count(nums[i])) continue; ) > ? m[nums[i]-]:); ) > ? m[nums[i]+]:); ; m[nums[i]] = sum; // 为什么要加这个,不是改变两端…

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…