用c实现的判断一个图是否有环，数据结构中的经典算法，输入一个图，然后判断是否有环。-used to achieve a judgment whether there are plans in Central and data structure of classical algorithm, the importation of a map, and then determine whether there is any ring.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002420s ]
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:0.105236s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002490s ]
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.002090s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003671s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002101s ]
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SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014976s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.002236s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 182184 [ RunTime:0.001247s ]
