How to get percentage of each group?

[MiaoMiao]

I have a table, containing userId and userType.
userId    userType
1    A
2    B
3    C
4    A
5    B
6    B

I want to get percentage of each userType.
My current solution:
1. Get count of each group via THRIFT
select
      userType
    , count(1)
from
    some_table
group by
    userType

2. Calculate each userType using other programming language like PHP.

This solution is fine, but I'm just curious, is there a way to do it
in one query?
I know this query works in mysql, but not hive.
select
      userType
    , count(1)/(select count(1) from some_table)
from
    some_table
group by
    userType