AlgorithmFriday_Week8

all_combinations.py

# First define the list of chars for all digits
num_dict = {'2': ['a', 'b', 'c'],
            '3': ['d', 'e', 'f'],
            '4': ['g', 'h', 'i'],
            '5': ['j', 'k', 'l'],
            '6': ['m', 'n', 'o'],
            '7': ['p', 'q', 'r', 's'],
            '8': ['t', 'u', 'v'],
            '9': ['w', 'x', 'y', 'z'],
            # just incase 0 and 1 is part of input, we can safely skip
            '0': [''], '1': [''],}
# using a recursive approach
def all_combinations(num):
    if num==None: return []
    try:
        num = str(num)
        if len(num)==0: return []
        if len(num)==1: return num_map[num]

        # function that returns comb of only 2 digits
        def comb_2(prev, next): return [x+y for x in prev for y in next]

        prev = num_dict[num[0]]
        for i in num[1:]:
            # print(prev)
            prev = comb_2(prev, num_dict[i])
        return prev
        
    except:
        return []

all_combinations(23)

Thank you @meekg33k.
I'm so excited