CIS 260 Recurse.java

Code

/*
    Recurse.java
    CIS 260
    4/6/05
    Dave Klick

    Recursion demonstration
*/

public class Recurse {
    public static void main(String[] args) {
        int i;
        for (i=0; i<10; i++)
            System.out.print(fact(i) + "  ");
        System.out.println();
        for (i=0; i<10; i++)
            System.out.print(fib(i) + "  ");
        System.out.println();
        countdown(10);
        toh(4);
    }

    static void toh(int n) {
        toh_move(n, 0, 2);
    }

    static void toh_move(int num, int from, int to) {
        int temp = 3 - from - to;
        if (num > 1) toh_move(num-1, from, temp);
        System.out.println("Move disk from pole " + from
            + " to pole " + to);
        if (num > 1) toh_move(num-1, temp, to);
    }

    static void countdown(int n) {
        if (n <= 0) System.out.println("Boom!");
        else {
            System.out.print(n + "...");
            pause(1);
            countdown(n-1);
        }
    }

    static void pause(int s) {
        try {
            Thread.sleep(s * 1000);
        } catch (Exception e) {}
    }

    static long fib(long n) {
        if (n < 2) return n;
        return fib(n-1) + fib(n-2);
    }

    static long fact(long n) {
        if (n < 2) return 1;
        return n * fact(n-1);
    }
}