【剑指Offer】跳台阶&变态跳台阶

class Solution {
public:
    int jumpFloor(int number) {
        if(number == 1) return 1;
        if(number == 2) return 2;
        return jumpFloor(number - 1) + jumpFloor(number - 2);
    }
};

class Solution {
public:
    int jumpFloor(int number) {
        int x = 1,y = 2, z;
        if(number == 1) return 1;
        if(number == 2) return 2;
        for(int i = 3; i <= number; ++i){
            z = y;
            y = x + y;
            x = z;
        }
        return y;
    }
};