时间函数

#include <windows.h> //取系统时间 LARGE_INTEGER tick, begin, end; QueryPerformanceFrequency(&tick); //取计数器频率 QueryPerformanceCounter(&begin); //取初始硬件定时器计数 //中间程序运行// QueryPerformanceCounter(&end); //获得终止硬件定时器计数 cout << "计数器频率：" << tick.QuadPart << "Hz" << endl; cout << "时钟计数 ：" << end.QuadPart - begin.QuadPart << endl; cout << setprecision(6) << (end.QuadPart - begin.QuadPart) / double(tick.QuadPart) << "秒" << endl;

延时循环

#include<ctime> 不啦不啦 float secs; cin>>secs; clock_t delay=secs*CLOCK_PER_SEC; clock_start=clock(); while(clock()-start<delay) ; //空语句

————数学函数————

向下取整函数floor(x)：

返回不超过x的最大整数。