《leetcode》longest-consecutive-sequence

题目：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) complexity.

解析：题目的意思是求最长的连续子序列长度，当然要求时间复杂度为O（n）。

import java.util.Arrays;
public class Solution {public int longestConsecutive(int[] num) {if(num.length==1){return 1;}int max=0;//最大的长度int count=1;//给当前连续的元素计数Arrays.sort(num);//先来个排序for(int i=1;i<num.length;i++){if((num[i]==num[i-1]+1)){//当前的元素是前一个元素+1count++;if(count>=max){max=count;}}else if ((num[i]==num[i-1])){//当前的元素和前一个元素一样，不计数if(count>=max){max=count;}continue;}else{//当前的元素不等于前一个元素，重新计数count=1;if(count>=max){max=count;}}}return max;}
}

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