C++编写延时循环有大神帮我一下吗？万分感谢！！！！

Question

#include "stdafx.h"
#include
#include
int _tmain(int argc, _TCHAR* argv[])
{
using namespace std;
cout << "输入延迟时间，以秒: ";
float secs;
cin >> secs;
clock_t delay = secs * CLOCKS_PER_SEC;
cout << "启程\a\n";
clock_t start = clock();
while (clock() - start < delay)
;
cout << "Done\a\n";
return 0;
}
//我有看不懂这个1：clock_t delay = secs * CLOCKS_PER_SEC;
2: clock_t start = clock();
3： while (clock() - start < delay)
;
有大神帮我一下吗？
万分感谢！！！！

Answer 1

 clock_t delay = secs * CLOCKS_PER_SEC;
每个时钟花费的时间乘以秒数=总延迟时间

while (clock() - start < delay)
clock等于时钟计数，它和初始相比小于delay说明时间不够，于是执行分号，空循环。
直到延迟足够

因此实现了延迟