main.cpp

经典的分油问题

#include <iostream>

using namespace std;

double single=200;
double useoil=300;

double tomile(double precost, double hive)
{
	if (hive==0)
	{
		if (precost>=single)
		{
			return single+tomile(precost-single, single);
		}
		else
		{
			return precost;
		}
	}
	else	//	hive>0
	{
		if (precost==0)	//	precost==0
		{
			return 0;
		}
		else	//	precost>0
		{
			int k;for(k=1;k*single<=hive;++k)	;

			double iback=-1;
			int bk;

			for(;;++k)
			{
				double stagelength=(k*single-hive)/(2*k-1);
				double newuse=stagelength*(2*k-1);

				if (newuse>precost||stagelength*2>=single)
					break;

				double newiback=stagelength+tomile(precost-newuse, hive+newuse);

				if (newiback>iback)
				{
					iback=newiback;
					bk=k;
				}
			}
			if (iback==-1)
			{
				for(k=2;(hive/k)+(precost*2/(2*k-1))>single;++k)	;
				return precost/(2*k-1);
			}
			else
			{
				return iback;
			}
		}	//	end of precost>0
	}	//	end of hive>0
}

int main()
{
	cout<<"Use Oil: "<<useoil<<endl;
	cout<<"Total mile: "<<tomile(useoil, 0)<<endl;
	return 0;
}