hardcore-algorithms.py

def bubsort(arr):
    if not arr: return None
    for i in range(len(arr)):
        for j in range(i+1, len(arr)):
            if arr[i] > arr[j]: arr[i], arr[j] = arr[j], arr[i]
    return arr

class Node(object):
    def __init__(self, val, l=None, r=None):
        self.val = val
        self.left = l
        self.right = r

def revtree(node):
    if not node: return None
    node.left, node.right = revtree(node.right), revtree(node.left)
    return node

def test():
    print(bubsort([1,2,3]))
    print(revtree(Node(1, Node(2), Node(3))).left.val)