* 9.4 Write a method to compute all permutations of a string. * * */ publicstaticvoidmain(String[]args){ Mainso=newMain(); System.out.println("method 2:"); HashMap<String,Integer>hs=newHashMap<String,Integer>(); so.permutation2("AABB",0,3,hs); } publicvoidpermutation2(Strings,int...