Combinations LeetCode solution in Java

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class Solution {
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  public List<List<Integer>> combine(int n, int k) {
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    List<List<Integer>> subsets = new ArrayList<>();
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    generatesubsets(1, n, new ArrayList(), subsets, k);
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    return subsets;
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  }
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  void generatesubsets(
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      int start, int n, List<Integer> current, List<List<Integer>> subsets, int k) {
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    if (current.size() == k) {
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      subsets.add(new ArrayList(current));
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    }
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    for (int i = start; i <= n; i++) {
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      current.add(i);
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      generatesubsets(i + 1, n, current, subsets, k);
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      current.remove(current.size() - 1);
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    }
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  }
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}