Alice has ahandof cards, given as an array of integers.

Now she wants to rearrange the cards into groups so that each group is sizeW, and consists ofWconsecutive cards.

Returntrueif and only if she can.

1. Example 1:

Input: 
hand = [1,2,3,6,2,3,4,7,8], W = 3

Output: 
true

Explanation:
 Alice's 
hand
 can be rearranged as 
[1,2,3],[2,3,4],[6,7,8]
.

Example 2:

Input: 
hand = [1,2,3,4,5], W = 4

Output: 
false

Explanation:
 Alice's 
hand
 can't be rearranged into groups of 
4
.

Note:

1. 1 < = hand.length < = 10000
2. 0 < = hand[i] < = 10^9
3. 1 < = W < = hand.length

class Solution {
    public boolean isNStraightHand(int[] hand, int W) {
        if (hand == null || hand.length == 0) return false;
        int n = hand.length;
        if (n < W || n % W != 0) return false;

        PriorityQueue<Integer> pq = new PriorityQueue<>();
        Map<Integer, Integer> hash = new HashMap<>();
        for (int i = 0; i < n; i++){
            pq.offer(hand[i]);
            hash.put(hand[i], hash.getOrDefault(hand[i], 0) + 1);
        }

        while (!pq.isEmpty()){
            int last = pq.poll();
            hash.put(last, hash.get(last) - 1);    
            if (hash.get(last) > 0) pq.offer(last);
            for (int i = 1; i < W; i++){
                int cur = last + 1;
                pq.remove(cur);
                if (!hash.containsKey(cur)) return false;
                last = cur;
                hash.put(cur, hash.get(cur) - 1);
                if (hash.get(cur) > 0) pq.offer(cur);
                //System.out.println("last: " + last + " cur: " + cur + " i: " + i + " count: " + hash.get(cur));
            }
        }

        return true;
    }
}