C++如何测量程序运行时间_C++高精度计时器实现方法

#include <iostream>
#include <chrono>
<p>int main() {
// 记录开始时间
auto start = std::chrono::high_resolution_clock::now();</p><pre class="brush:php;toolbar:false;"><pre class="brush:php;toolbar:false;">// 要测量的代码段
for (int i = 0; i < 1000000; ++i) {
    // 模拟工作
}

// 记录结束时间
auto end = std::chrono::high_resolution_clock::now();

// 计算耗时（微秒）
auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);

std::cout << "执行时间：" << duration.count() << " 微秒" << std::endl;

return 0;

auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
std::cout << "耗时：" << ms.count() << " ms";

#include <chrono>
#include <iostream>
<p>class Timer {
public:
Timer() { start_ = std::chrono::high_resolution_clock::now(); }</p><pre class="brush:php;toolbar:false;"><pre class="brush:php;toolbar:false;">void reset() { start_ = std::chrono::high_resolution_clock::now(); }

int64_t elapsed_ms() const {
    auto now = std::chrono::high_resolution_clock::now();
    auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_);
    return duration.count();
}

Timer t;
// 执行任务
std::cout << "耗时：" << t.elapsed_ms() << " ms";