Even Odd Tree LeetCode solution in Java

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class Solution {
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  public boolean isEvenOddTree(TreeNode root) {
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    Queue<TreeNode> qu = new LinkedList<>();
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    qu.add(root);
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    boolean even = true; // maintain check for levels
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    while (qu.size() > 0) {
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      int size = qu.size();
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      int prev =
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          (even) ? 0 : Integer.MAX_VALUE; // start prev with 0 to check strictly increasing and
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      // Integer_MAX_VALUE to check strictly decreasing
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      while (size-- > 0) {
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        TreeNode rem = qu.remove();
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        if (even) {
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          if (rem.val % 2 == 0
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              || rem.val
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                  <= prev) { // false if value at even level is even or not strictly increasing
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            return false;
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          }
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        } else {
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          if (rem.val % 2 != 0
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              || rem.val >= prev) { // false if value at odd level is odd or not strictly decreasing
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            return false;
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          }
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        }
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        if (rem.left != null) {
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          qu.add(rem.left);
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        }
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        if (rem.right != null) {
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          qu.add(rem.right);
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        }
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        prev = rem.val; // update previous
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      }
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      even = !even; // change level
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    }
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    return true;
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  }
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}