# C#LeetCode刷题之#594-最长和谐子序列​​​​​​​​​​​​​​（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.

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.

```public class Program {

public static void Main(string[] args) {
var nums = new int[] { 1, 3, 2, 2, 5, 2, 3, 7 };

var res = FindLHS(nums);
Console.WriteLine(res);

}

public static int FindLHS(int[] nums) {
var res = 0;
var dic = new Dictionary<int, int>();
for(var i = 0; i < nums.Length; i++) {
if(dic.ContainsKey(nums[i])) {
dic[nums[i]]++;
} else {
dic[nums[i]] = 1;
}
}
foreach(var item in dic) {
if(dic.ContainsKey(item.Key + 1)) {
res = Math.Max(res, dic[item.Key + 1] + item.Value);
}
if(dic.ContainsKey(item.Key - 1)) {
res = Math.Max(res, dic[item.Key - 1] + item.Value);
}
}
return res;
}

}```

`5`