How to create a tree like structure with a List<CustomType> parameter in java constructor-CodePudding

I have a class Org that has name and a list of tasks and I want to print a list of tasks under each name in a tree like structure using the class constructor:
name -> A tasks - > B, C, name ->B tasks - > D, E, name -> C, tasks -> F,G

        A
       / \
     B     C
    / \   / \
   D   E  F  G

Here is the class structure:

static class Org {
        char name;
        List<Org> tasks;

        Org(char name, List<Org> tasks){
            this.name = name;
            this.tasks = tasks;
        }

I read this but it does not apply to what I'm doing. Here is what I tried

 List<Org> org = new Org('A', new ArrayList<Org>('B','C')); // for the first level
 org.add('B', new ArrayList<Org>('D','E')); // for the second level
 org.add('C', new ArrayList<Org>('F','G')); // for the third level

This does not work because the second parameter in the constructor expects an Org type and not a char type. How would you create such a tree using this constructor? Any help would be appreciated.

CodePudding user response：

For these problems, we should tackle it bottom up.

Org orgG = new Org('G', Arrays.asList());
Org orgF = new Org('F', Arrays.asList());
Org orgE = new Org('E', Arrays.asList());
Org orgD = new Org('D', Arrays.asList());
        
Org orgC = new Org('C', Arrays.asList(orgF, orgG));
Org orgB = new Org('B', Arrays.asList(orgD, orgE));
Org orgA = new Org('A', Arrays.asList(orgC, orgB));

With this, if Org has empty list means it is a leaf node (no child for it).

CodePudding user response：

You have to start from the bottom up, constructing the child object and passing it to the parent constructor. For the sake of brevity, I'll substitute Org... for List<Org>:

new Org('A',
    new Org('B',
        new Org('D'), new Org('E')),
    new Org('C',
        new Org('F'), new Org('G')))

CodePudding user response：

For the benefit of anyone who faces a similar issue, I was able to get what I needed with this based on the comments and answers provided by contributors.

            Org orgG = new Org('G', new ArrayList());
            Org orgF = new Org('F', new ArrayList());
            Org orgE = new Org('E', new ArrayList());
            Org orgD = new Org('D', Arrays.asList(orgH,orgI));
            Org orgC = new Org('C', Arrays.asList(orgF,orgG));
            Org orgB = new Org('B', Arrays.asList(orgD,orgE));
            Org orgA = new Org('A', Arrays.asList(orgB,orgC));