human
I found an interesting problem on https://leetcode.com/problems/longest-harmonious-subsequence/:
We define a harmonious array is an array where the difference between its maximum value and its minimum value is exactly 1.

Now, given an integer array, you need to find the length of its longest harmonious subsequence among all its possible subsequences.

Example 1:

Input: [1,3,2,2,5,2,3,7]
Output: 5
Explanation: The longest harmonious subsequence is [3,2,2,2,3].


Note:
The length of the input array will not exceed 20,000.

I tried it in Python, but could not do it. Can you solve it?

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Can you provide a Python program to find the length of its longest harmonious subsequence among all its possible subsequences?
assistant
#Here is Python program to find the length of its longest harmonious subsequence among all its possible subsequences.

class Solution:
     def findLHS(self, nums):
         """
         :type nums: List[int]
         :rtype: int
         """
         count = collections.Counter(nums)
         ret = 0
         for i in count:
             if i+1 in count:
                 ret = max(ret, count[i]+count[i+1])
        
         return ret