How to create a tree with the number of child nodes being decided at run time?

Question

As far as i know trees are created using structures and the trees i have created have always had nodes with the same no. of child nodes which is decided at compile time, like

struct node
{
int data;
struct node *left,*right;
};

which has 2 child nodes decided during compile time.How do i decide the no. of child nodes(which is constant for all nodes) during run time? Also is it possible to create a tree in which the child nodes for every node are decided during run time?

Answer 1

Here's a simple way to do it in Python (2.7) : you pass a list of children to the constructor, so you can decide on how many children you need at when you run the code:

class TreeNode:
    def __init__(self, data):
        self.data = data
        self.children = []

    def add_children(self, child):
        self.children.append(child)

    def __str__(self):
        return str(self.data)

    def print_tree(self, root):
        if root is None:
            return
        print root.data
        for child in root.children:
            self.print_tree(child)

r = TreeNode(0)
ch1 = TreeNode(1)
ch2 = TreeNode(2)
ch3 = TreeNode(3)
r.add_children(ch1)
r.add_children(ch2)
r.add_children(ch3)
ch4 = TreeNode(4)
ch1.add_achildren(ch4)

>>> r.print_tree(r)
0
1
4
2
3

'>>>' is run from the interpreter.