如何将无序的多边形顶点集合，排序成逆时针顺序!这个正是凸包算法前面的一些准备工作!-how to disorderly polygon vertex assembly, sequencing into a counter-clockwise order! This is why the convex hull algorithm front of some preparation work!
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.002042s ]
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:0.136648s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.000997s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001692s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001422s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.005477s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001186s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.006866s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015231s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001654s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 319515 [ RunTime:0.015342s ]
