写一段C++代码，从test.dat中将每个块的”块数据区数据”提取出来，并存放在body的文件夹中，文件名使用“块ID.bin”的命名方式(如 块ID为12，则文件名为 “12.bin”)

#include <fstream>
#include <cstdint>
#include <cstdlib>
#include <cstring>

void extractBlockData(const char* filename) {
    std::ifstream fin(filename, std::ios::binary);
    if (!fin.is_open()) {
        std::cerr << "Failed to open file: " << filename << std::endl;
        return;
    }

    const int kBlockSize = 16 + 4 + 4;
    const int kHeaderSize = 16 + 4 + 4;
    const int kMaxPointCount = 1024;

    uint8_t* pPointData = new uint8_t[kMaxPointCount];
    char* pFilename = new char[64];
    memset(pFilename, 0, 64);

    for (int i = 0; i < 32; i++) {
        fin.seekg(i * kBlockSize, std::ios::beg);

        uint32_t u32Mask = 0;
        int block_id = 0;
        int block_data_len = 0;
        fin.read(reinterpret_cast<char*>(&u32Mask), sizeof(u32Mask));
        fin.read(reinterpret_cast<char*>(&block_id), sizeof(block_id));
        fin.read(reinterpret_cast<char*>(&block_data_len), sizeof(block_data_len));

        if (u32Mask != 0xF4F3F2F1 || block_data_len > kMaxPointCount) {
            std::cerr << "Invalid block data at block " << block_id << std::endl;
            continue;
        }

        fin.read(reinterpret_cast<char*>(pPointData), block_data_len);
        sprintf(pFilename, "body/%d.bin", block_id);
        std::ofstream fout(pFilename, std::ios::binary);
        if (!fout.is_open()) {
            std::cerr << "Failed to create file: " << pFilename << std::endl;
            continue;
        }
        fout.write(reinterpret_cast<char*>(pPointData), block_data_len);
        fout.close();
    }

    delete[] pFilename;
    delete[] pPointData;
}

这段代码中，`kBlockSize` 表示每个块的大小，`kHeaderSize` 表示块头的大小，`kMaxPointCount` 表示块数据区最大的数据长度。首先读取每个块的块头，判断是否符合要求，然后读取块数据区数据并写入到对应的文件中。