<p>We define a harmonious array as an array where the difference between its maximum value and its minimum value is <b>exactly</b> <code>1</code>.</p>

<p>Given an integer array <code>nums</code>, return <em>the length of its longest harmonious subsequence among all its possible subsequences</em>.</p>

<p>A <strong>subsequence</strong> 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.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

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

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4]
<strong>Output:</strong> 2
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,1,1,1]
<strong>Output:</strong> 0
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2 * 10<sup>4</sup></code></li>
	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
</ul>
class Solution {
public:
    int findLHS(vector<int>& nums) {
        map<int,int> mp;
        int output=0;
        for(int i=0;i<nums.size();i++){
            mp[nums[i]]++;
        }

        map<int,int>::iterator it,it2;
        for(it=mp.begin();it!=prev(mp.end());it++){
            it2=next(it);
            if(it2->first-it->first==1){
                if(it2->second+it->second>output){
                    output=it2->second+it->second;
                }
            }
        }
        return output;
    }
};
// class Solution {
// public:
//     int findLHS(vector<int>& nums) {
//         int res=0,l=0,r=1,cur=0;
//         sort(nums.begin(),nums.end());
//         while(r<nums.size()){
//             if(nums[r]-nums[l]==1){
//                 res = max(res,r-l+1);
//             }
//            while(nums[r]-nums[l]>1){
//             ++l;
//            }
//            ++r;
//         }
//         return res;
//     }
// };
45400