We define a harmonious array as an array where the difference between its maximum value and its minimum value is?exactly?1.

Given an integer array?nums, return?the length of its longest harmonious subsequence among all its possible subsequences.

A?subsequence?of array is a sequence that can be derived from the array by deleting some or no elements without changing the order of the remaining elements.

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Example 1:

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

Example 2:

Input: nums = [1,2,3,4]Output: 2

Example 3:

Input: nums = [1,1,1,1]Output: 0

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Constraints:

• 1 <= nums.length <= 2 * 104

• -109?<= nums[i] <= 109

如果是要連續(xù)的序列的話，就需要sliding window了。

Runtime:?46 ms, faster than?25.00%?of?Java?online submissions for?Longest Harmonious Subsequence.

Memory Usage:?68.2 MB, less than?22.61%?of?Java?online submissions for?Longest Harmonious Subsequence.