根据贪心算法，来求解最小生成树；
这种情况，可能求不不全局最优解，但是，可以求出当前情况下的最优解；-According to greedy algorithm to solve the minimum spanning tree this situation, it may not seek the global optimal solution is not, however, you can find the optimal solution under the current situation
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001375s ]
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:0.084258s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001139s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001157s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000950s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003052s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000859s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.004007s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.026703s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001670s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 209183 [ RunTime:0.015169s ]
