from itertools import combinations


def generate_combinations(n, suffix):
    # 所有可能的单个字母
    letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

    # 对 n=1 的特殊处理
    if n == 1:
        return [c + suffix for c in letters]

    # 1. n 个字母完全相同的组合
    repeated_combinations = [c * n for c in letters]

    # 2. (n-1) 个字母相同，一个不同的组合 (仅当 n > 1)
    double_repeats = []
    if n > 1:
        for c1 in letters:
            for c2 in letters:
                if c1 != c2:
                    # 确保字母按字母表顺序排列，避免重复
                    combination = ''.join(sorted([c1] * (n - 1) + [c2]))
                    if combination not in double_repeats:
                        double_repeats.append(combination)

    # 3. n 个字母不完全相同的组合 (仅当 n > 1)
    unique_combinations = []
    if n > 1:
        unique_combinations = [''.join(sorted(comb)) for comb in combinations(letters, n) if len(set(comb)) == n]

    # 合并所有组合
    all_combinations = repeated_combinations + double_repeats + unique_combinations

    # 将所有组合拼接后缀
    final_combinations = [combo + suffix for combo in all_combinations]

    return final_combinations

if __name__ == '__main__':
    n = 2  # 可以输入不同的长度
    suffix = '.de'  # 可以输入不同的后缀

    # 生成组合并打印
    combinations = generate_combinations(n, suffix)
    print(combinations)
    print(f"生成的组合数量: {len(combinations)}")