421a.cpp

来自「C++实训教程」· C++ 代码 · 共 64 行

//421a.cpp using class FTimer
#include "FTimer.H"
const unsigned long MAXNUM = 1000000L; //1M
main(void)
{
	FTimer t0,t1,t2;
   unsigned long TestNum, Current;
   //project 0
    	t0.Start();
		for(TestNum = 3; TestNum<MAXNUM; TestNum++)
		{
		     Current=TestNum;
	        do
           {
			    if(Current%2)
					Current  = 3*Current+1;
				else
					Current /= 2;
           }while(Current!=1);
		}
      t0.Stop();
      cout << "The Project0 total time = " ;
      t0.DisplayDeltaTime();

   //project 1
    	t1.Start();
		for(TestNum = 3; TestNum<MAXNUM; TestNum+=2)
		{
		     Current=TestNum;
	        do
           {
			    if(Current%2)
					Current  = 3*Current+1;
				else
					Current /= 2;
           }while(Current > TestNum);
		}
      t1.Stop();
      cout << "The Project1 total time = " ;
      t1.DisplayDeltaTime();

   //project 2
    	t2.Start();
		for(TestNum = 3; TestNum<MAXNUM; TestNum+=2)
		{
		     Current=TestNum;
	        do
           {
			    if(Current%2)
					Current  = Current++  + (Current>>1) ;
				else
					Current /= 2;
           }while(Current > TestNum);
		}
      t2.Stop();
      cout << "The Project2 total time = " ;
      t2.DisplayDeltaTime();
	return(0);
}
/*
The Project0 total time = 6980mS
The Project1 total time = 220mS
The Project2 total time = 110mS
*/