clock时钟周期
            
            
              cpp
              
              
            
          
          #include <iostream>
#include <ctime>
int main() {
    clock_t start = clock();  // 获取开始时间的时钟周期数
    // 模拟一些工作
    for (long long i = 0; i < 10000000000; ++i);
    clock_t end = clock();  // 获取结束时间的时钟周期数
    std::cout << "start: " << static_cast<double>(start) / CLOCKS_PER_SEC << " seconds" << std::endl;
    std::cout << "end: " << static_cast<double>(end) / CLOCKS_PER_SEC << " seconds" << std::endl;
    // 计算所用时间(秒)
    double elapsed_time = static_cast<double>(end - start) / CLOCKS_PER_SEC;
    std::cout << "Elapsed time: " << elapsed_time << " seconds" << std::endl;
    return 0;
}
/*
start: 0.51 seconds
end: 3.087 seconds
Elapsed time: 2.577 seconds
*/