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Generating List with Variable Entries/Arguments

Answer 1

+1 A:

This is a very common situation, addressed by both the Relational Db model and, for example, XML.

Datastructures cannot be NP problems, but a algorithm applied to your library might be.

If you make the number of levels variable, it will require some meta-programming.

Henk Holterman 2010-07-15 10:43:50

Answer 2

+1 A:

Does this problem fall in the NP class of problems?

No, but generating all combinations has exponential time complexity in the depth of the section system (book-chapter-etc).

If you you have a way of determining if the current structure (e.g. chapter) should have children, you can do the following:

// The int value is the number of children
Tuple<string, int> GetChildStructure(string parentStructure) {
    if(parentStructure == "Library") return new Tuple<string, int>("Book", 3);
    if(parentStructure == "Book") return new Tuple<string, int>("Chapter", 2);
    // ...
    // You can get these from a config file/DB/etc
    return null;
}

void BuildStructure(Structure parent) {
   var childStruct = GetChildStructure(parent.StructName);
   if(childStruct != null) {
      for(int i=1; i <= childStruct.Item2; i++) {
         Structure child = new Structure(childStruct.Item1,  i);
         BuildStructure(child);
      }
   }
}

void Main() {
    var lib = new Structure("Library", 1);
    BuildStructure(lib);
}

You should also check this post out.

Mau 2010-07-15 10:47:50

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Generating List with Variable Entries/Arguments

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