CH18_NewMath.java

public class NewMath
{
    //iterative pow() method!
    public static int pow(int base, int exp)
    {
        int prod = 1;
        for(int i=0; i<exp; i++)
        {
            prod*=base;
        }
        return prod;
    }

    //how the Math class does pow()!!
    public static double pow(double base, double exp)
    {
        return Math.exp(exp*Math.log(base));
    }

    //recursive pow() method!!!
    public static double pow(double base, int exp)
    {
        if(exp==0)
        {
            return 1;
        }
        return base*pow(base,exp-1);
    }

    //another recursive method, now for factorials
    public static int fact(int num)
    {
        if(num==0)
        {
            return 1;
        }
        return num*fact(num-1);
    }

    //recursing in public! evaluate nCr
    public static int pascal(int row, int col)
    {
        if(col==0 || row==col)
        {
            return 1;
        }
        return pascal(row-1,col)+pascal(row-1,col-1);
    }

    //recursing in public! find one row of pascal's triangle
    public static String pascalRow(int n)
    {
        String temp = "";
        for(int i=0; i<=n; i++)
        {
            temp += pascal(n,i) + "\t";
        }
        return temp;
    }

    //recursing in public! print out pascal's triangle
    public static String pascalTri(int n)
    {
        String temp = "";
        for(int i=0; i<=n; i++)
        {
            temp += pascalRow(i) + "\n";
        }
        return temp;
    }

    //find fibonacci sequence terms
    public static int fib(int n)
    {
        if(n==0 || n==1){return 1;}
        return fib(n-1)+fib(n-2);
    }
}