How can I remove the repeat solution of 24 points game?

[Guan Kangle]

Hi all,

I made a program that can obtain all the solutions of four numbers ranging from 1 to 13, but there are always repeat solutions such as:

（3+（3/7））*7
（（3/7）+3）*7
7*（3+（3/7））
7*（（3/7）+3）

Is there any good idea to remove the redundant combinations?

[hamsterman]

It's not hard to tell (write a function which can tell) that all of those are the same.
Do post your algorithm though. There may be ways better than filtering the results.