斐波那契数列算法，青蛙跳台阶

青蛙跳台阶，一次可跳一阶或两阶，跳到第n阶时有几种跳法

package com.art.arithmetic.count;

public class FrogJumpOrder {

	public static void main(String[] args) {
		FrogJumpOrder frogJumpOrder = new FrogJumpOrder();
		System.out.println(frogJumpOrder.getMethodNum(4));
		System.out.println(frogJumpOrder.getMethodNum(5));
		System.out.println(frogJumpOrder.getMethodNum(6));
		System.out.println(frogJumpOrder.getMethodNum(7));
		System.out.println(frogJumpOrder.getMethodNum(8));
	}
	
	/**
	 * 能跳到第n阶的方式有从n-1阶跳或从n-2阶跳，那么就需要获取跳到n-1和n-2时各有多少种方法，依次类推
	 * @return
	 */
	public long getMethodNum(long n) {
		if (n < 1) {
			return 0;
		}
		if (n == 1) {
			return 1;
		}
		if (n == 2) {
			return 2;
		}
		return getMethodNum(n-1) + getMethodNum(n-2);
	}

}