<p>Alice has some number of cards and she wants to rearrange the cards into groups so that each group is of size <code>groupSize</code>, and consists of <code>groupSize</code> consecutive cards.</p>

<p>Given an integer array <code>hand</code> where <code>hand[i]</code> is the value written on the <code>i<sup>th</sup></code> card and an integer <code>groupSize</code>, return <code>true</code> if she can rearrange the cards, or <code>false</code> otherwise.</p>

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

<pre>
<strong>Input:</strong> hand = [1,2,3,6,2,3,4,7,8], groupSize = 3
<strong>Output:</strong> true
<strong>Explanation:</strong> Alice&#39;s hand can be rearranged as [1,2,3],[2,3,4],[6,7,8]
</pre>

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

<pre>
<strong>Input:</strong> hand = [1,2,3,4,5], groupSize = 4
<strong>Output:</strong> false
<strong>Explanation:</strong> Alice&#39;s hand can not be rearranged into groups of 4.

</pre>

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

<ul>
	<li><code>1 &lt;= hand.length &lt;= 10<sup>4</sup></code></li>
	<li><code>0 &lt;= hand[i] &lt;= 10<sup>9</sup></code></li>
	<li><code>1 &lt;= groupSize &lt;= hand.length</code></li>
</ul>

<p>&nbsp;</p>
<p><strong>Note:</strong> This question is the same as 1296: <a href="https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers/" target="_blank">https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers/</a></p>

class Solution {
private: 
    bool solve(priority_queue<int, vector<int>, greater<int>>&pq, int n,int prev)
    {
        if(n == 1 && pq.top() != prev ){
            //cout<<pq.top()<<" ";
            pq.pop();
            return true;
        }
        int num = pq.top();
        pq.pop();
        if(pq.empty()){
            return false;
        }
        if(pq.top() == num+1){
           //cout<<num<<"  ";
            return solve(pq,n-1,num);
        }
        else if(pq.top() == num)
        {
            if(solve(pq,n,num))
            {
                pq.push(num);
                return true;
            } 
        }
        return false;
    }
public:
    bool isNStraightHand(vector<int>& hand, int groupSize) 
    {
       if(hand.size()%groupSize != 0){
        return false;
       }
       priority_queue<int, vector<int>, greater<int>>pq;
       for(int i: hand)
       {
        pq.push(i);
       }
       int n = groupSize;
       while(!pq.empty())
       {
        if(pq.size()%n != 0)return false;
        if(!solve(pq,n,-1)){
            return false;
        }
       }
       return true;  
    }
};
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