Fibonacci.java

import java.math.BigInteger;

/**
 * 피보나치 수열을 구하는 클래스입니다.
 * 피보나치 수열이 뭔가요? http://ko.wikipedia.org/wiki/%ED%94%BC%EB%B3%B4%EB%82%98%EC%B9%98_%EC%88%98
 */
public class Fibonacci{
     public static void main(String []args){
         if (args.length == 0) {
             print_usage(Fibonacci.class.getName());
             return;
         }
         int start = Integer.parseInt(args[0]);
         fibonacci(start);
     }

    public static void fibonacci(int start)
    {
        BigInteger fib1 = new BigInteger("0");
        BigInteger fib2 = new BigInteger("1");
        for(int i = 0; i <= (start -2); i++) {
            BigInteger fib3 = fib1.add(fib2);
            System.out.println("F"+ i + " = " + fib1 + ", F" + (i+1) + " = " + fib2 + ", F" + (i+2) + " =  " + fib3);
            fib1 = fib2;
            fib2 = fib3;
        }
    }
     public static void print_usage(String progname) {
         String usage = String.format("usage) java %s <number>\n   eg) java %s 5", progname, progname) ;
         System.out.println(usage);
     }
}