Problems with an Algorithm
I have the following 5 lines of string:
A.B.C.D.E
A.B
A.B.C
A
A.B.C.D
This are hierarchical relationships. The second row for example means that B is a child of A.
Now I want to parse these lines into a Class Structure. So that each letter is represented by an instance of a class and points to its parent (or null if top level (A)). However, every letter should only be addded once.
I started the following:
String[] hierarchical = Name.Split('.');
if (hierarchical.Count() > 1)
{
Console.WriteLine("Package '" + Name + "' is not top level and has to be parsed");
Console.WriteLine("Find parent for '" + hierarchical[hierarchical.Count() - 1] + "'");
findParent(Name);
}
else
{
Console.WriteLine("Package '" + Name + "' is top level and is added to the manager");
if (!manager.isAlreadyAdded(Name))
{
Package p = new Package(null, hierarchical[0], Name);
manager.add(p);
}
}
}
This means if it is a top level name (A in the example above) then add it to the manager if it is not already there. The problem lies in the findParent() method where I try to find the parent of a subpackage:
private void findParent(String path)
{
String originalPath = path;
bool found = false;
while (!found)
{
int position = path.LastIndexOf(".");
if (position == -1)
{
Console.WriteLine("Top level reached: " + path);
if (!manager.isAlreadyAdded(path))
{
Package p = new Package(null, path, path);
manager.add(p);
}
fo开发者_运维问答und = true;
}
else
{
path = path.Substring(0, position);
Console.WriteLine("Path: " + path);
if (!manager.isAlreadyAdded(path))
{
Package p = new Package(null,getName(path), path);
manager.add(p);
}
}
}
}
private string getName(string path)
{
int position = path.LastIndexOf(".");
if (position == -1)
{
return path;
}
else
{
return path.Substring(position+1, path.Length - position - 1);
}
}
As expected this works not as I wanted, since it adds all packages as top levels. How can I correct this?
Is the first argument of the Package constructor by any chance the parent? If so, you are always passing null there which could be your issue.
Btw, I think you may be able to simplify your algorithm.
Can't something like this work:
String[] hierarchical = Name.Split('.');
foreach (String node in hierarchical){
if(!manager.Contains(node)){
manager.AddToEnd(node); //adds node who's parent is the last node added
}
}
Since each line is guaranteed to be "sorted" you know if you get a package that hasn't been added yet, its parent is the last node already added.
I'm a little unclear on what you're trying to do, but this will set parent
to the second to last entry (node) in your list:
string[] nodes = path.Split(".".ToCharArray());
string parent = nodes[nodes.Length - 2];
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