d4r4.cpp

来自「Visual C++ 常用数值算法集 源代码」· C++ 代码 · 共 36 行

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

void main()
{
    //program d4r4
    //driver for routine factln
    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,"Log 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;           
		cout<<setw(3)<<x;
		cout<<setprecision(8)<<setw(18)<<log(actual);
		cout<<setprecision(8)<<setw(18)<<factln(x)<<endl;			
    }
}