Currently I'm representing a binary tree in the following manner:
[None,2,[None,3,None]]
The tree above is rooted at 2. None means that the branch is empty.
I'd rather implement this in a list. Are there better ways to do this (without resorting to creating classes) ?
If you want to represent a complete binary tree (i.e. with all nodes having two children, except the leaves), then you can use just a flat list the represent the tree.
You can easily determine the father and two children of a node like this:
def leftChild(lst,i):
try:
return lst[i*2]
except IndexError:
return None
def rightChild(lst,i):
try:
return lst[i*2+1]
except IndexError:
return None
def father(lst,i):
try:
return lst[i/2]
except IndexError:
return None
It is possible to represent a binary tree using a flat list, as described here. How wasteful this method is would depend on the shape of your tree.
I am curious as to why you insist on avoiding classes. If you were to wrap this in a class, you could define a clean API and hide the details of your implementation from the eventual user.
Here is my way: an array of arrays, where item with index 0 is a root item:
[['Level A', 'A1', 'A2'], ['Level B', 'B1', 'B2'], ['Level C', 'C1', 'C2']]
Classes can make a simple application unnecessarily complex, especially if you deal with simple trees like represented above.
