题解 | 数据分类处理

# 读取输入
I_line = input().split()
I_num, I_data = int(I_line[0]), I_line[1:]

R_line = input().split()
R_count, R_data = int(R_line[0]), R_line[1:]

# 规范化R数据
R_data = sorted(set(R_data), key=int)

# 处理每个规则
result = []
for r in R_data:
    matches = [(str(i), val) for i, val in enumerate(I_data) if r in val]
    if matches:
        result.extend([r, str(len(matches))])
        for idx, val in matches:
            result.extend([idx, val])

# 输出结果
output = [str(len(result))] + result
print(" ".join(output))