二叉树的递归算法：计算高度、结点个数、交换左右儿子
问题的描述
写一完整函数，计算树的结点数目int CountNode(BTNode* &t)；
完善以下两个函数：
计算树的高度int Depth(BTNode* &root)；
对树的所有子树交换左右孩子void swapsons(BTNode* &t)；-Binary Tree Recursive Algorithm: Calculate the height of node number, the exchange about the issue of his son to write a complete description of function, calculating the number of tree node int CountNode (BTNode
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.000930s ]
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:0.074323s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001049s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001052s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000952s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003028s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000886s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003617s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014933s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001190s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 162428 [ RunTime:0.015710s ]
