Question

I have a user and group database. There are a lot of groups on the database and each group has a lot of member. For example;

• User1 is member of Group1, Group2, Group3
• User2 is member of Group2
• User3 is member of Group2, Group5

There is a parent-child relationship among the groups. Parent groups are more general groups. For example,

• Group2: Programmers
• Group5: .NET Programmers

On the database, there is no parent-child relationship among the groups. How can create dynamic parent-child relationship? I there any algorithm about these problem?

Thanks for reply.

Answer 1

Iterate through every item, filling table child1Parent2[groups,groups]. At start it is full of trues. For every group check condition: g1 is set and g2 is not set. If it is true, set false to chuld1Parent2[gr1,gr2]. At the end of iteration you have the table wich contains all parent-child info.

boolean child1Parent2[groups,groups];
for( g1:groups) for(g2:groups) {
    child1Parent2[g1,g2]=true;
}
for (itemRow:rows){
    for( g1:groups) for(g2:groups)
        if (child1Parent2[g1,g2])
        if (itemRow.contains(g1)& !itemRow.contains(g2))
            child1Parent2[g1,g2]=false;
}

As a result you have: child1Parent2[g1,g2] === (g1 is a child of g2)

A piece of advice for future: if you want to find some info, think about how this info will be declared, what structure could it have. You’ll understand much more on the subject.