Closest Room LeetCode solution in Java

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class Solution {
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  public int[] closestRoom(int[][] rooms, int[][] queries) {
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    int n = rooms.length, k = queries.length;
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    Integer[] indexes = new Integer[k];
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    for (int i = 0; i < k; i++) indexes[i] = i;
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    Arrays.sort(
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        rooms, (a, b) -> Integer.compare(b[1], a[1])); // Sort by decreasing order of room size
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    Arrays.sort(
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        indexes,
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        (a, b) ->
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            Integer.compare(
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                queries[b][1], queries[a][1])); // Sort by decreasing order of query minSize
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    TreeSet<Integer> roomIdsSoFar = new TreeSet<>();
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    int[] ans = new int[k];
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    int i = 0;
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    for (int index : indexes) {
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      while (i < n
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          && rooms[i][1]
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              >= queries[index][1]) { // Add id of the room which its size >= query minSize
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        roomIdsSoFar.add(rooms[i++][0]);
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      }
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      ans[index] = searchClosetRoomId(roomIdsSoFar, queries[index][0]);
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    }
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    return ans;
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  }
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  int searchClosetRoomId(TreeSet<Integer> treeSet, int preferredId) {
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    Integer floor = treeSet.floor(preferredId);
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    Integer ceiling = treeSet.ceiling(preferredId);
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    int ansAbs = Integer.MAX_VALUE, ans = -1;
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    if (floor != null) {
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      ans = floor;
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      ansAbs = Math.abs(preferredId - floor);
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    }
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    if (ceiling != null && ansAbs > Math.abs(preferredId - ceiling)) {
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      ans = ceiling;
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    }
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    return ans;
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  }
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}