zlib 解压缩 c++

好的，关于 zlib 解压缩 c++，你可以使用 zlib 库来实现。具体步骤如下：

1. 引入头文件：`#include <zlib.h>`
2. 定义一个 `z_stream` 结构体变量，用于存储解压缩的相关信息：`z_stream stream;`
3. 初始化 `z_stream` 变量：`stream.zalloc = Z_NULL; stream.zfree = Z_NULL; stream.opaque = Z_NULL; stream.avail_in = 0; stream.next_in = Z_NULL;`
4. 调用 `inflateInit2()` 函数初始化解压缩环境：`int ret = inflateInit2(&stream, MAX_WBITS + 16);`
5. 循环调用 `inflate()` 函数进行解压缩，直到解压缩完成：`while (ret != Z_STREAM_END) { ... }`
6. 调用 `inflateEnd()` 函数释放解压缩环境：`inflateEnd(&stream);`
7. 获取解压缩后的数据：`char* out = (char*)stream.next_out;`

下面是一个简单的示例代码：

#include <iostream>
#include <zlib.h>

int main() {
    // 压缩数据
    const char* data = "Hello, world!";
    uLong data_len = strlen(data);
    uLong compress_len = compressBound(data_len);
    Bytef* compress_data = new Bytef[compress_len];    compress(compress_data, &compress_len, (const Bytef*)data, data_len);

    // 解压缩数据
    z_stream stream;
    stream.zalloc = Z_NULL;
    stream.zfree = Z_NULL;
    stream.opaque = Z_NULL;
    stream.avail_in = 0;
    stream.next_in = Z_NULL;
    int ret = inflateInit2(&stream, MAX_WBITS + 16);
    if (ret != Z_OK) {
        std::cerr << "inflateInit2 error: " << ret << std::endl;
        return -1;
    }
    stream.avail_in = compress_len;
    stream.next_in = compress_data;
    char* out = new char[data_len + 1];
    while (ret != Z_STREAM_END) {
        stream.avail_out = data_len;
        stream.next_out = (Bytef*)out;
        ret = inflate(&stream, Z_NO_FLUSH);
        if (ret == Z_STREAM_ERROR) {
            std::cerr << "inflate error: " << ret << std::endl;
            return -1;
        }
        std::cout << out;
    }
    inflateEnd(&stream);

    delete[] compress_data;
    delete[] out;

    return 0;
}