I have tried so many times , but i have no idea to avoid tle.
I use memory search to solve it , and get tle on #58.
Although i use random method when i choose a node , but it doesn't work.
I just know that somebody have accepted this problem use the same method one years ago.
Maybe he also get tle after rejudged.
e...I think this is a NP problem.
Could anybody help me?
Thank you!
sorry for my poor English.
ありがとう ございます。

I use C++ stl map to save information.
And it's a Red-Black Tree(O(logn)).
Will it be faster if i use hash(O(1)) instead of map?
If anybody know how to solve it , please tell me.
Here is my e-mail : 419481620@qq.com.

I also have tried to use hash instead of map to save information.
But still tle #58.
Here is my code.
After i accept , i will delete my code (if i could get accept , and i wish so , haha...).
[code deleted].

Edited by author 13.04.2011 08:22

Oh ! after i use a new way to random , i got tle #69 now.
faint.

I think that jury has some ideas for quick algo without random absolutely.
Try to find mathematical ways to speed up.

Oh ! I got AC now.
Just a little Optimization.