在不使用itertools的情况下使用重复生成组合

def repeated_combinations(elements, length):
    combinations = []

    def helper(current_combination, remaining_length):
        if remaining_length == 0:
            combinations.append(list(current_combination))
            return
        for element in elements:
            current_combination.append(element)
            helper(current_combination, remaining_length - 1)
            current_combination.pop()

    helper([], length)
    return combinations

elements = ['A', 'B', 'C']
length = 2
result = repeated_combinations(elements, length)
print(result)

[['A', 'A'], ['A', 'B'], ['A', 'C'], ['B', 'A'], ['B', 'B'], ['B', 'C'], ['C', 'A'], ['C', 'B'], ['C', 'C']]