C++ 计算时间差

参考【C++】计算时间差 - CrazyTomato - 博客园

1.clock()

标准库中ctime头文件

#include 
#include 

using namespace std;

int main(){
    clock_t start = clock();      //获取当前系统时间
    
    function();

    clock_t end  = clock();

    double programTimes = ((double) end -start) / CLOCKS_PER_SEC;
}

2.high_resolution_clock

chrono (C++11新增程序库) 

#include 
#include 
#include 

using namespace std;

int main(){
    auto beginTime = std::chrono::high_resolution_clock::now();

    std::this_thread::sleep_for(std::chrono::milliseconds(20));

    auto endTime = std::chrono::high_resolution_clock::now();
    auto elapsedTime = std::chrono::duration_cast(endTime-beginTime);

    double programTimes = ((double) elapsedTime.count(); //programTimes：20000
}

• seconds (): 返回秒计的unix时间戳
• milliseconds (): 返回毫秒计的unix时间戳
• microseconds (): 返回微秒计的unix时间戳