深圳某匠的笔试题，据说基本都考的这几个

HRESULT function()
{
    HRESULT error = S_OK;
    if (FAILED(Operation1()))
    {
        return OPERATION1FAILED;
    }
    if (FAILED(Operation2()))
    {
        return OPERATION2FAILED;
    }
    if (FAILED(Operation3()))
    {
        return OPERATION3FAILED;
    }
    if (FAILED(Operation4()))
    {
        return OPERATION4FAILED;
    }
    return S_OK;
}

def find_all_pairs(arr, target):
    seen = {}
    pairs = set()
    for num in arr:
        complement = target - num
        if complement in seen:
            # 用元组存储并排序，避免重复（如(2,3)和(3,2)视为同一对）
            pair = tuple(sorted((num, complement)))
            pairs.add(pair)
        seen[num] = True
    return list(pairs)

def ip_to_int(ip):
    # 分割IP为4个部分
    parts = list(map(int, ip.split('.')))
    # 确保IP格式正确（4个0-255的整数）
    if len(parts) != 4 or any(p < 0 or p > 255 for p in parts):
        raise ValueError("Invalid IP address")
    # 转换公式：a*256^3 + b*256^2 + c*256 + d
    return parts[0] * (256**3) + parts[1] * (256**2) + parts[2] * 256 + parts[3]

CREATE TABLE ip_country (
    id INT PRIMARY KEY AUTO_INCREMENT,
    start_ip_int BIGINT NOT NULL,  -- 起始IP转换后的整数
    end_ip_int BIGINT NOT NULL,    -- 结束IP转换后的整数
    country VARCHAR(50) NOT NULL   -- 国家名
);

-- 针对范围查询优化，建立联合索引
CREATE INDEX idx_ip_range ON ip_country (start_ip_int, end_ip_int);

SELECT country 
FROM ip_country 
WHERE target_ip_int BETWEEN start_ip_int AND end_ip_int 
LIMIT 1;  -- IP段不重叠，只返回一条结果

ZADD ip_segments 起始IP整数 "国家名,结束IP整数"
# 示例：ZADD ip_segments 0 "CN,16914248" （对应0.0.0.0-1.5.7.8的转换后整数范围）

ZREVRANGEBYSCORE ip_segments target_ip -inf LIMIT 0 1