substrings.py

def get_all_substrings(arr, index, subarr, record):
    if index == len(arr):
        if len(subarr) != 0:
            record.append(''.join(subarr))
    else:
        get_all_substrings(arr, index + 1, subarr, record)
        get_all_substrings(arr, index + 1, subarr + [arr[index]], record)

    return record


def check(initial, target):
    substrings = get_all_substrings(initial, 0, [], [])
    length = len(target)
    counter = 0
    index = 0
    reverse_idx = length
    while reverse_idx != index:
        if target[index:reverse_idx] in substrings:
            counter += 1
            index = reverse_idx
            reverse_idx = length
        else:
            reverse_idx -= 1
    if reverse_idx != length and reverse_idx == index:
        return -1
    else:
        return counter