A BinarySearchTree to use for HackerRank problems.

BinarySearchTree.py

###
# Python 3
# T = [int, BinarySearchTree, BinarySearchTree, int] or None
###
def size(T):
    return T[3] if not T is None else 0
def is_empty(T):
    return T is None
def v(T):
    return T[0]
def left(T):
    return T[1]
def right(T):
    return T[2]
def insert(T, x):
    if T is None:
        return [x, None, None, 1]
    if x == T[0]:
        return T
    T[3] += 1
    if x < T[0]:
        T[1] = insert(T[1], x)
    else:
        T[2] = insert(T[2], x)
    return T
def remove(T, x):
    if T is None:
        return None
    if x == T[0]:
        if T[1] is None and T[2] is None:
            return None
        if not T[1] is None:
            T[0] = T[1][0]
            T[3] -= T[1][3]
            T[1] = remove(T[1], T[1][0])
            T[3] += T[1][3] if not T[1] is None else 0
        else:
            T[0] = T[2][0]
            T[3] -= T[2][3]
            T[2] = remove(T[2], T[2][0])
            T[3] += T[2][3] if not T[2] is None else 0
    elif x < T[0]:
        T[3] -= T[1][3] if not T[1] is None else 0
        T[1] = remove(T[1], x)
        T[3] += T[1][3] if not T[1] is None else 0
    else:
        T[3] -= T[2][3] if not T[2] is None else 0
        T[2] = remove(T[2], x)
        T[3] += T[2][3] if not T[2] is None else 0
    return T
# The End