Array
128. Longest Consecutive Sequence
Given an unsorted array of integers, find the length of the longest consecutive elements sequence.
Your algorithm should run in O(n) complexity. (要求了复杂度)
即 找出给定无序数组中最长连续子列的长度
- 举个例子：
Input:
Output:
上述例子中最长连续子列是,所以返回
class Solution:
def longestConsecutive(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
longest_streak = 0
num_set = set(nums)
for num in num_set:
if num - 1 not in num_set:
current_num = num
current_streak = 1
while current_num + 1 in num_set:
current_num += 1
current_streak += 1
longest_streak = max(longest_streak, current_streak)
return longest_streak
