bug-for- ~Tree()

Tree::~Tree()
{
	if(_cartreeArray!=NULL)
	{
		for(int i=0;i<_nodeNum;++i)
		{
			if(_cartreeArray[i]!=NULL)
			{
				delete _cartreeArray[i];
				_cartreeArray[i]=NULL;
			}
		}
		delete[] _cartreeArray;
		_cartreeArray=NULL;
	}
}

error! about delete