如何从给定的句子中找到可以构成给定缩写的方式的数量

def count_abbreviations(sentence, abbreviation):
    words = sentence.split()
    abbreviation_combinations = generate_abbreviation_combinations(abbreviation)
    count = 0

    for combination in abbreviation_combinations:
        remaining_words = words[:]
        for letter in combination:
            found_word = False
            for word in remaining_words:
                if word.startswith(letter):
                    remaining_words.remove(word)
                    found_word = True
                    break
            if not found_word:
                break
        if not remaining_words:
            count += 1

    return count

def generate_abbreviation_combinations(abbreviation):
    combinations = []
    n = len(abbreviation)

    def backtrack(combination, start):
        if len(combination) == n:
            combinations.append(combination)
            return
        for i in range(start, n):
            backtrack(combination + abbreviation[i], i + 1)

    backtrack("", 0)
    return combinations

# 示例用法
sentence = "Artificial Intelligence and Big Data"
abbreviation = "AIBD"
count = count_abbreviations(sentence, abbreviation)
print(count)  # 输出：2