PHP实现线性表的顺序存储结构

classSqList
{public$elem;
    public$length;
    public$size;
}

classLinear
{const LIST_INIT_SIZE = 10;
    const LIST_INCREMENT = 5;
    private$list = null;

    /**
     * 构造一个空的线性表
     */publicfunctioninitList()
    {$this->list = new SqList();
        $this->list->elem = array();
        $this->list->length = 0;
        $this->list->size = self::LIST_INIT_SIZE;
        returntrue;
    }

    /**
     * 销毁线性表
     */publicfunctiondestoryList()
    {if (is_object($this->list)) {
            $this->list = null;
        }
    }

    /**
     * 是否为空表
     */publicfunctionlistEmpty()
    {if (is_object($this->list)) {
            return$this->list->length == 0 ? true : false;
        }
    }

    /**
     * 返回元素个数
     */publicfunctionlistLength()
    {if (is_object($this->list)) {
            return$this->list->length;
        }
    }

    /**
     * 获取指定位置的元素
     */publicfunctiongetElem($i)
    {if ($i 1