Divide Array in Sets of K Consecutive Numbers LeetCode solution in Java

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class Solution {
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  public boolean isPossibleDivide(int[] nums, int k) {
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    if (nums.length % k != 0) return false;
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    Map<Integer, Integer> countMap = new HashMap<>();
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    for (int num : nums) {
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      int count = countMap.getOrDefault(num, 0);
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      countMap.put(num, count + 1);
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    }
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    Arrays.sort(nums);
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    for (int num : nums) {
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      if (!countMap.containsKey(num)) continue;
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      int count = countMap.get(num);
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      if (count == 1) countMap.remove(num);
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      else countMap.put(num, count - 1);
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      for (int i = 1; i < k; i++) {
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        int next = num + i;
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        if (!countMap.containsKey(next)) return false;
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        count = countMap.get(next);
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        if (count == 1) countMap.remove(next);
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        else countMap.put(next, count - 1);
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      }
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    }
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    return true;
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  }
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}