<p>Given an integer array <code>nums</code> and an integer <code>k</code>, return <em>the number of <strong>good subarrays</strong> of </em><code>nums</code>.</p>

<p>A <strong>good array</strong> is an array where the number of different integers in that array is exactly <code>k</code>.</p>

<ul>
	<li>For example, <code>[1,2,3,1,2]</code> has <code>3</code> different integers: <code>1</code>, <code>2</code>, and <code>3</code>.</li>
</ul>

<p>A <strong>subarray</strong> is a <strong>contiguous</strong> part of an array.</p>

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

<pre>
<strong>Input:</strong> nums = [1,2,1,2,3], k = 2
<strong>Output:</strong> 7
<strong>Explanation:</strong> Subarrays formed with exactly 2 different integers: [1,2], [2,1], [1,2], [2,3], [1,2,1], [2,1,2], [1,2,1,2]
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,2,1,3,4], k = 3
<strong>Output:</strong> 3
<strong>Explanation:</strong> Subarrays formed with exactly 3 different integers: [1,2,1,3], [2,1,3], [1,3,4].
</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>1 &lt;= nums[i], k &lt;= nums.length</code></li>
</ul>

class Solution {
public:

    int Atleastkintegers(vector<int>& nums, int k){
        int ws = 0, we = 0;
        int n = nums.size();

        int unique = 0, count = 0;
        map<int,int> Hashmap;

        while(we < n){
            if(Hashmap.find(nums[we]) == Hashmap.end() || Hashmap[nums[we]] == 0){
                unique++;
                Hashmap[nums[we]] = 1;
            }
            else Hashmap[nums[we]]++;
                
            if(unique > k){
                while(unique > k && ws<=we){
                    Hashmap[nums[ws]]--;
                    if(Hashmap[nums[ws]] == 0)
                        unique--;
                    ws++;
                }
            }

            if(unique <= k) count = count + (we - ws + 1);
            //cout<<ws<<" "<<we<<endl;
            we++;
        }

        return count;
    }

    int subarraysWithKDistinct(vector<int>& nums, int k) {

        int count1 = Atleastkintegers(nums,k);
        int count2 = Atleastkintegers(nums,k-1);
        cout<<count1<<" "<<count2<<" "<<endl;
        return count1 - count2;
    }
};
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