c++ - C/C++ 中的算法速度测试器

Question

我必须以毫秒为单位计算算法的速度。在 C++/C 中，我该怎么做？我需要在输入之前和输出之后写 smth 但到底是什么？？

Answer 1

你可以使用 clock()来自 <time.h> 的函数
clock()显示自程序启动以来经过了多少滴答。宏CLOCKS_PER_SEC包含每秒滴答数，因此您实际上可以获得时间。

//We start measuring here. Remember what was the amount of ticks in the 
//beginning of the part of code you want to test:
int start = clock();
//<...>
//Do your stuff here
//<...>
int end = clock();//Now check what amount of ticks we have now. 
//To get the time, just subtract start from end, and divide by CLOCKS_PER_SEC.
std::cout << "it took " << end - start << "ticks, or " << ((float)end - start)/CLOCKS_PER_SEC << "seconds." << std::endl;