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:0.001067s ]
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:0.119496s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001602s ]
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001286s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003438s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000928s ]
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SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001205s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 182184 [ RunTime:0.012078s ]
