maths.hpp

// maths.hpp
// some arbitrary math functions
// converted from C to C++
// pedantically perfect, in Allman with 4 spaces

#include <iostream>
using namespace std;

// count by x, from 0 to e
void countby(int x, int e)
{
    int n;

    for(n = 0; n <= e; n += x)
    {
        cout << n;
    }
    cout << endl;

    return;
}

// calculate continued fractions 
double cfrac(int a, int n)
{ 
    int k = 1;
    double c = a + 1.000 / a;   // This has got to be wrong.

    c = a + 1.000 / c;          // I'll look up the formula and see
    while(++k < n-1)            // how I can make this better.
    {         
        c = a + 1.000 / c;
    }

    return c;
}

// two implementations of a factorial function 
// accurate only with 0 < n <= 12
int factorial_r(int n)
{
    if (n == 1)
    {
        return 1;
    }
    else
    {
        return n * factorial_r(n - 1);
    }
}

int factorial_f(int n)
{
    for (int i = n - 1; i > 1; i--)
    {
        n = n * i;
    }

    return n;
}