Hand of Straights LeetCode solution in Java

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class Solution {
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  public boolean isNStraightHand(int[] hand, int groupSize) {
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    if (hand.length % groupSize != 0) return false;
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    Map<Integer, Integer> map = new HashMap<>();
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    PriorityQueue<Integer> minHeap = new PriorityQueue<>();
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    for (int card : hand) {
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      if (map.containsKey(card)) map.put(card, map.get(card) + 1);
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      else {
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        map.put(card, 1);
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        minHeap.add(card);
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      }
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    }
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    while (!minHeap.isEmpty()) {
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      int min = minHeap.peek();
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      for (int i = min; i < min + groupSize; i++) {
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        if (!map.containsKey(i) || map.get(i) == 0) return false;
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        map.put(i, map.get(i) - 1);
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        if (map.get(i) == 0) {
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          if (minHeap.peek() != i) return false;
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          minHeap.poll();
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        }
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      }
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    }
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    return true;
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  }
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}