Sorting

Sorting
https://goo.gl/EY9P3X

Tower of Hanoi

https://goo.gl/CSY6c6

send gmail

step 1:please read the policy of gmail http://stackoverflow.com/questions/20337040/gmail-smtp-debug-error-please-log-in-via-your-web-browser step 2: ex: http://stackoverflow.com/questions/17332384/python-3-send-email-smtp-gmail-error-smtpexception ex: no chinese in code http://johnisacoolboy.pixnet.net/blog/post/148222978-python-email%E5%AF%84%E4%BF%A1%E6%A8%A1%E7%B5%84%E7%9A%84%E4%BD%BF%E7%94%A8%E6%96%B9%E5%BC%8F

OID Pen

principle: http://thps0612.blogspot.tw/2015/06/blog-post_23.html https://www.youtube.com/watch?v=A6yKZ1wjUgg https://www.youtube.com/watch?v=JViaNBbwpfQ https://www.youtube.com/watch?v=4AjvjFM8GzM