C++ 计时

ctime

clock()是一个无参函数，返回值是一个以毫秒为单位的整形

    #include <ctime>
    #include <iostream>

    long t1 = clock();
    ****
    Doing something
    ****
    long t2 = clock();;
    std::cout << t2 - t1 << "ms\n";

chrono

    #include <chrono>
    #include <iostream>

    std::chrono::time_point<std::chrono::steady_clock> t1 = std::chrono::steady_clock::now();
    ****
    Doing something
    ****
    std::chrono::time_point<std::chrono::steady_clock> t2 = std::chrono::steady_clock::now();
    std::chrono::duration<double> elapsed1 = t2 - t1;
    std::cout << "t2 - t1: " << elapsed1.count() << "s\n" << std::endl;
    std::cout << "t2 - t1: " << std::chrono::duration_cast<std::chrono::milliseconds>(elapsed1).count() << "ms\n"<< std::endl;

参考链接

https://www.cnblogs.com/jwk000/p/3560086.html
https://en.cppreference.com/w/cpp/chrono
https://en.cppreference.com/w/cpp/chrono/duration