import java.util.*;
//动态规划
//设置dp【n】为到达n阶的跳法数,状态转移方程为dp【n】 = dp【n-1】 + dp【n-2】
//因为n- 2阶和n-1都可以一步跳到n

public class Solution {
    public int jumpFloor (int number) {

        if (number ==1){
            return 1;
        }else if (number == 2){
            return  2;
        }

        int[] dp = new int[number + 1 ];

        dp[0] = 0;
        dp[1] = 1;
        dp[2] = 2;

        for (int i = 3; i <= number ; i++) {
            dp[i] = dp[i-2] + dp[i-1];
        }
        return dp[number];
    }
}