青蛙跳

<pre name="code" class="java">    N块石头，青蛙在第1块石头上。青蛙跳，每次只能跳1个或者2个。问跳到第N块石头一共有多少种不同的跳法  

public class FrogJump {public static int frogJumpWays(int n){if(n == 1 || n ==2){return 1;}int tmp = 1;int num1 = 1;int num2 = 1;for(int i = 2; i < n; i++){tmp = num2;num2 += num1;num1 = tmp;}return num2;}public static void main(String[] args){System.out.println(frogJumpWays(4));System.out.println(frogJumpWays(6));System.out.println(frogJumpWays(40));}}