算出前几项就可以找到此规律

class Solution {
public:
    int jumpFloor(int number) {
        int a[10010];
        a[0] = 0, a[1] = 1, a[2] = 2;
        for ( int i = 3; i < 10010; i++ ) a[i] = a[i-1] + a[i-2];
        return a[number];
    }
};