<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>

#define ll long long 
class Solution {
public:
    int subarraysWithKDistinct(vector<int>& v, int k) {
        ll cnt=0;
        ll n=v.size();
        map<ll,ll>m;
        ll idx=-1;
        set<ll>s;
        for(ll i=0;i<n;i++){
            m[v[i]]++;
            if(m.size()==k){
                idx=i;
                break;
            }
        }
        ll j=0;
        for(auto x:m)s.insert(x.first);
        ll prev=0;
        if(idx==-1)return 0;
        for(ll i=idx;i<n;i++){
            if(i!=idx)m[v[i]]++;
            while(j<n && m[v[j]]>1){
                m[v[j]]--;
                j++;                
            }
            cout<<i<<" "<<j<<" "<<prev<<endl;
            cnt+=j-prev+1;

            if(i+1<n && m[v[i+1]]==0){
                m[v[j]]--;
                j++;
                prev=j;
            }
        }
        return cnt;
    }
};
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