Update quicksort.c

//just have a try by liuzemin
 This is a push by liuzemin for a try.Good!
Merge remote-tracking branch 'fuhu/master'
Merge branch 'local' of https://github.com/liuzemin/basic-algorithm
Create acm
Delete acm
   Add HDU ACM.
Merge branch 'master' of https://github.com/liuzemin/basic-algorithm
Merge pull request #3 from liuzemin/master

Add HDU ACM