PHP Find All (somewhat) Unique Combinations of an Array

Question

I\'ve been looking at PHP array permutation / combination questions all day.. and still can\'t figure it out :/

If I have an array like:

20 //key bei         


        

Answer 1

The Idea is simple. Suppose you know how to permute, then if you save these permutations in a set it becomes a combinations. Set by definition takes care of the duplicate values. The Php euqivalent of Set or HashSet is SplObjectStorage and ArrayList is Array. It should not be hard to rewrite. I have an implementation in Java:

public static HashSet> permuteWithoutDuplicate(ArrayList input){
          if(input.size()==1){
              HashSet> b=new HashSet>();
              b.add(input);
              return b;
          }
          HashSet>ret= new HashSet>();
          int len=input.size();
          for(int i=0;i>temp=permuteWithoutDuplicate(new ArrayList(input));
              for(ArrayList t:temp)
                  t.add(a);
              ret.addAll(temp);
              input.add(i, a);
          }
          return ret;
      }