charlie-challenge.py

# challenge from charlie
#-----
# Write a function called "reconcileHelper" that processes two arrays of integers.
# Each array passed in will have only distinct numbers (no repeats of the same integer in 
# the same array), and the arrays are not sorted.
# Your job is to find out which numbers are in array a, but not array b, 
# and which numbers are in array b, but not in array a.
# Your function should return a string formatted as so:
# "Numbers in array a that aren't in array b: 
# <num1> <num2> <num3>...
# Numbers in array b that aren't in array a: 
# <num1> <num2> <num3>...
# "
# Each list of numbers should be listed in ascending order (lowest to largest)
# So for instance, if I passed in: 
# reconcileHelper([5, 3, 4], [4, 3, 10, 6])
# The function would return this multiline string:
# "Numbers in array a that aren't in array b: 
# 5
# Numbers in array b that aren't in array a: 
# 6 10
# ---

# imports
import numpy as np

# the function
def reconcileHelper(a, b):
    """the function, needs two arrays a and b"""
    
    # coerce to numpy array
    # TODO checks + assertions
    a = np.array(a)
    b = np.array(b)

    # make sets
    a = set(a)
    b = set(b)

    # a not b
    a_not_b = a.difference(b)

    # b not a
    b_not_a = b.difference(a)

    # return statements
    print("Numbers in array a that aren't in array b:")
    print(" ".join(str(x) for x in a_not_b))
    print("Numbers in array b that aren't in array a:")
    print(" ".join(str(x) for x in b_not_a))

    # return
    return None

# test
a = [1,2,3]
b = [3,4,5]
reconcileHelper(a,b)