题解 | #跳台阶#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param number int整型 
     * @return int整型
     */
    public int jumpFloor (int number) {
        int[] a = new int[number+1];
        int c = 0;
        if(number <= 0){
            return 0;
        }
           if(number == 1){
            return 1;
        }
            if(number == 2){
            return 2;
        }
        for(int i=1;i<=number;i++){
            c = jumpFloor2(i,a);
            a[i] = c;
        }
        return a[number];
    }

    public int jumpFloor2(int number,int[] a){
        if(a[number] !=0){
            return a[number];
        }
         int c = 1;
        int b = 2;

        int d = 0;
         for(int i=2;i<=number;i++){
            d =c+b;
            c= b;
            b = d;
        }
        return c;

    }
}