3个递归小练习

public class RecursionTest {

    
    /**
     * 求n的阶乘
     */
    private static int jiecheng(int n) {
        if (n==1) {
            return 1;
        }
        return n*jiecheng(n-1);
    }
    
    /**
     * 1 1 2 3 5 8 13 21 34 55 89 144
     * 求斐波那契数列的第N项
     * @param n
     * @return
     */
    private static int feibonaqi(int n) {
        if(n==1 || n==2) {
            return 1;
        }else {
            return feibonaqi(n-1)+feibonaqi(n-2);
        }
    }
    
    /**
     * 汉诺塔问题
     * @param n 一共有N个盘子
     * @param start 初始位置
     * @param middle 中介
     * @param end 目标位置
     */
    private static void hanota(int n, String start, String middle, String end) {
        if (n==1) {
            System.out.println("move from "+start+" to "+end);
        }else {
            hanota(n-1, start, end, middle);
            System.out.println("move from "+start+" to "+end);
            hanota(n-1, middle, start, end);
        }
    }
     
    
    public static void main(String[] args) {
        System.out.println(jiecheng(5));
        System.out.println(feibonaqi(5));
        System.out.println(feibonaqi(30));
        hanota(7, "left", "middle", "right");
    }
}