设计算法判断一个算术表达式的圆括号是否正确配对。 (提示：
对表达式进行扫描，凡遇到 ( 就进栈，遇 ) 就退掉栈顶的 ( ，表达式被扫描完毕，栈应为空。-Design algorithm to determine an arithmetic expression is correct matching parentheses. (Hint: regular expressions to scan for, in any case where (in the case into the stack, the event) on the Top-to return the (, expression was scanned, the stack should be empty.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001902s ]
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:0.170355s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001181s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.003243s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.003868s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.005759s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002571s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.004550s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.016892s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001375s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 273448 [ RunTime:0.178379s ]
