通过理解检查列表中的项目是否在其他2D列表中丢失

def check_missing_items(check_list, other_2d_list):
    # 将2D列表转换为集合
    other_set = set(item for sublist in other_2d_list for item in sublist)
    
    # 检查检查列表中的项目是否在集合中存在
    missing_items = [item for item in check_list if item not in other_set]
    
    return missing_items

# 示例数据
check_list = [1, 2, 3, 4, 5]
other_2d_list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

# 调用函数并打印结果
missing_items = check_missing_items(check_list, other_2d_list)
print("丢失的项目：", missing_items)

def check_missing_items_efficient(check_list, other_2d_list):
    # 将2D列表转换为哈希表
    other_dict = {}
    for sublist in other_2d_list:
        for item in sublist:
            other_dict[item] = True
    
    # 检查检查列表中的项目是否在哈希表中存在
    missing_items = [item for item in check_list if item not in other_dict]
    
    return missing_items

# 示例数据（大数据量）
check_list = list(range(1, 1000001))
other_2d_list = [list(range(1, 500001)), list(range(500001, 1000001)), list(range(1000001, 1500001))]

# 调用函数并打印结果（注意：大数据量情况下，运行时间可能较长）
missing_items = check_missing_items_efficient(check_list, other_2d_list)
print("丢失的项目：", missing_items)