/// <summary>
/// 是否达到平衡
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="p"></param>
/// <returns></returns>
public static bool AvlBalanced <T>(this BinNode <T> p) where T : IComparable <T>
{
return(p.BalFac() > -2 && p.BalFac() < 2);
}