一个用vc实现的Kruskal算法，程序流程非常清晰，有助于对算法的理解。-a vc achieved using Kruskal algorithm, program flow is very clear, contribute to the understanding of the algorithm.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001310s ]
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:0.087963s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001229s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001884s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001249s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003922s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001105s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003218s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014621s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001335s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 320698 [ RunTime:0.001317s ]
