d4r02.cpp

VC实现的常用数值计算方法

#include <iostream.h>
#include <math.h>
#include <iomanip.h>
#include <stdlib.h>
#include <fstream.h>
#include <string>

void main()
{
    //program d4r2
    //driver for routine factrl
    int i,x;
	char text[20];
    double nval,actual; 
    const double pi = 3.1415926;
    fstream fin;
    fin.open("d:\\vc常用数值算法集\\data\\fncval.dat",ios::in);
    while (strcmp(text,"N-factorial")!=0)
	{
      fin>>text;
	}
    fin>>nval; 
    cout<<text<<" "<<endl;
    fin>>text;
    cout<<endl;
    cout<<"   x            actual         facval(n)"<<endl;
    for( i = 1;i<=nval;i++)
	{
        fin>>x;
		fin>>actual;
            if (actual<10000000000.0)
			{
				cout<<setw(4)<<x;
				cout<<setw(18)<<actual;
				cout<<setw(18)<<factrl(x)<<endl;
			}
            else 
			{
				cout<<setw(4)<<x;
				cout<<setw(18)<<actual;
				cout<<setw(18)<<factrl(x)<<endl;
			}
    }
}