Check if a given Binary Tree is a Binary Search Tree

BinarySearchTreeTest

  public static void main(String ... args)
  {
    isBST(root, Integer.MAX_VALUE, Integer.MIN_VALUE);
  }
  
  private boolean isBST(TreeNode node, int max, int min)
	{
		boolean left = false;
		boolean right = false;
		if(node.left != null)
		{
			if(node.left.value > node.value || node.left.value < min)
			{
				return false;
			}
			left = isBST(node.left, node.value, min);
		}
		else
		{
			left = true;
		}
		
		if(node.right != null)
		{
			if(node.right.value < node.value || node.right.value > max)
			{
				return false;
			}
			right = isBST(node.right, max, node.value);
		}
		else
		{
			right = true;
		}
		return left && right;
	}