class Solution {

public:

    int jumpFloor(int number) {

        //斐波那契数列问题的扩展

        if(number<=0){ //非法输入检测

            return 0;

        }else if(number<=2){  //起始一级和两级台阶

            return number;

        }

        int pre_2=1,pre_1=2,curr=0;

        for(int i= 3;i<=number;i++){ //使用循环求解斐波那契数列

            curr=pre_2+pre_1;

            pre_2=pre_1;

            pre_1=curr;

        }

        return curr;

    }

};