128. Longest Consecutive Sequence

Given an unsorted array of integers nums, return the length of the longest consecutive elements sequence.

Example 1:

Input: nums = [100,4,200,1,3,2]
Output: 4
Explanation: The longest consecutive elements sequence is [1, 2, 3, 4]. Therefore its length is 4.

Example 2:

Input: nums = [0,3,7,2,5,8,4,6,0,1]
Output: 9

最大連續子字串，先排序，再看各值跟上個是不是差1

T: O(n), S: O(n)
class Solution:class Solution:
    def longestConsecutive(self, nums: List[int]) -> int:
        if not nums: return 0
        longest=current=1
        nums=list(sorted(set(nums)))
        print ("nums=",nums)
        for i in range(1,len(nums)): # start from 1
            if nums[i]==nums[i-1]+1:
                current+=1
            else: # not consecutive
                longest=max(current,longest)
                current=1
        return max(current,longest)

---

如果你覺得這篇文章很棒，請你不吝點讚 (ﾟ∀ﾟ)