I have worked through the questions for a software engineering position quite a while back, and while most of the problems were rather boring, there are some quite nice ones in there, for example there is a very simple and nice solution to this one:

  Given a Data Structure having first n integers 
  and next n chars. A = i1 i2 i3 ... iN c1 c2 
  c3 ... cN. Write an in-place algorithm to rearrange 
  the elements of the array ass A = i1 c1 i2 c2 ... 
  iN cN.