Question

I have a BST in python, with each node holding 3 pieces of data. Those pieces of data being ID, Mark, and Name.

What I’m trying to do is search for a Name, but the nodes are based on IDs, this is how I’ve searched. The function is supposed to output the ID of the specific Name.

def findName(tree,name):
    if tree==None:
        return None
    elif tree['name']==name:
        return tree['id']
    if tree['left']!=None:
        return findName(tree['left'],name)
    if tree['right']!=None:
        return findName(tree['right'],name) 

Unfortunately I’ll only ever be searching the left side of the Tree, and not the right, the opposite applies if I search the right side first.

How do I search both sides for this?

Answer 1

You shouldn’t return if you’re not yet finished! Instead, you can replace your last 4 lines with a single, short-circuiting or:

return findName(tree['left'], name) or findName(tree['right'], name)

Make sure your IDs don’t include 0, though, otherwise this method will fail because 0 is a falsy value, just like None.