该程序完成对二叉树的非递归中序遍历，因为其中涉及到二叉树的构造，而且使用类来构造，所以代码比较多。-completion of the process of non- recursive binary tree which preorder because it involved the construction of a binary tree, but the use of class structure, the code more.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001358s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.094448s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001270s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002111s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001258s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003579s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001093s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003234s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015176s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001501s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 117289 [ RunTime:0.001321s ]
