ctime(部分)

clock_t    //  system  typedef   for clock()  return    (long    in vc++6.0)

clock()   // get system time

CLOCKS_PER_SEC   //    system  time  /  sec

time(0);//  include <cstdlib>         srand(time(0));     rand();
//////////////////////////////////////////////////////////////////////////////////////////////////
#include <iostream>
//#include <cstring>
//#include <string>
#include <ctime>                                //ctime为调用clock()
int main()
{
 using namespace std;
    cout<<"enter delay time:(sec)"<<endl;
 float secs;
 cin>>secs;
 cout<<"you must wait for "<<secs<<" secs"<<endl;
 clock_t delay=secs;                          //clock_t为 typedef定义的类型别名
 clock_t start=clock()/CLOCKS_PER_SEC;        //CLOCKS_PER_SEC为 系统单位时间/每秒
 cout<<"the start is: "<<start<<endl;
 clock_t aa=start;
 cout<<"the aa is: "<<aa<<endl;
 int flag=0;
 while((clock()/CLOCKS_PER_SEC+1-start)<delay)//控制结束，必须加1，让时间正常结束
 {
  if (secs==0)
   ;
  else
  {     
   if(flag==0)                         //第一秒内容输出
   {
  
           cout<<start-start+1<<"<--->"<<start<<"<--->";
        cout<<"please wait(the first)"<<endl;
     flag=1;
   }
    
            if((clock()/CLOCKS_PER_SEC-aa)==1) //第一秒后内容输出
   {
     cout<<clock()/CLOCKS_PER_SEC-start+1<<"<--->"<<"the \"clock()/CLOCKS_PER_SEC\" is "
      <<clock()/CLOCKS_PER_SEC<<"<--->";
        cout<<"please wait"<<endl;
                 aa=clock()/CLOCKS_PER_SEC;
   }
        }
 }
 //因为提前结束一秒所以结果加一秒
 cout<<"at the last you wait:"<<clock()/CLOCKS_PER_SEC-start+1<<" secs"<<endl;

    return 0;
}
// strcat strcpy strlen strcmp
//clock()
//CLOCKS_PER_SEC