一个可以实现加减乘除以及带括号的计算器，用数据结构知识中的数栈编写而成-A calculation can be achieved as well as the brackets with the calculator, and knowledge of data structure has been prepared by a number of stack
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.003008s ]
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:0.147672s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002997s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.003773s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002921s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003755s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002358s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003877s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014928s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.002702s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 261202 [ RunTime:0.001376s ]
