如何提高C++大数据开发中的数据拆解速度?

#include 
#include 

void splitStringWithPointer(const char* str)
{
    char* p = strtok(const_cast(str), " ");
    while (p != nullptr)
    {
        std::cout << p << std::endl;
        p = strtok(nullptr, " ");
    }
}

int main()
{
    const char* str = "Hello World";
    splitStringWithPointer(str);

    return 0;
}

#include 
#include 
#include 
 
void splitStringWithReference(const std::string& str)
{
    size_t start = 0;
    size_t end = str.find(' ');
    
    while (end != std::string::npos)
    {
        std::cout << str.substr(start, end - start) << std::endl;
        start = end + 1;
        end = str.find(' ', start);
    }
    
    std::cout << str.substr(start, end - start) << std::endl;
}
 
int main()
{
    std::string str = "Hello World";
    splitStringWithReference(str);
 
    return 0;
}

#include 
#include 
#include 
 
void splitStringInThread(const std::string& str, size_t start, size_t end)
{
    size_t startIndex = start;
    size_t endIndex = end;
    size_t pos = str.find(' ', startIndex);
    
    while (pos <= endIndex)
    {
        std::cout << str.substr(startIndex, pos - startIndex) << std::endl;
        startIndex = pos + 1;
        pos = str.find(' ', startIndex);
    }
 
    std::cout << str.substr(startIndex, endIndex - startIndex) << std::endl;
}
 
int main()
{
    std::string str = "Hello World";
    const int threadNum = 4;
    std::vector threads;
    
    size_t dataSize = str.size();
    size_t stepSize = dataSize / threadNum;
    
    for (int i = 0; i < threadNum; ++i)
    {
        size_t start = i * stepSize;
        size_t end = (i != (threadNum - 1)) ? (start + stepSize) : (dataSize - 1);
        threads.emplace_back(splitStringInThread, std::ref(str), start, end);
    }
    
    for (auto& thread : threads)
    {
        thread.join();
    }
 
    return 0;
}