有时候需要比较两个函数运行时间的快慢，需要用到计时器。找有关计时器的资料？找到了花了时间去看还不一定会用。这个代码就是用于测试C/C++语言写的程序的运行时间，有秒，毫秒，和微秒级别。-Sometimes the speed of the running time of the need to compare two functions need to use the timer. Find the timer information? Found not necessarily with took the time to look. This code is used for the the write test the C/C++ language program run time, seconds, milliseconds and microseconds level.