这个题目，和前面的楼梯的题目代码一样样
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.util.StringTokenizer;public class Main {public static void main(String[] args) throws Exception{BufferedReader reader=new BufferedReader(new InputStreamReader(System.in));StringTokenizer st=new StringTokenizer(reader.readLine());int a=Integer.parseInt(st.nextToken());int b=Integer.parseInt(st.nextToken());int N=b-a;BigDecimal[] arr=new BigDecimal[N+1];if(N==0){System.out.println(0);return;}else if(N==1){System.out.println(1);return;}else if(N==2){System.out.println(2);return;}arr[1]=new BigDecimal(1);arr[2]=new BigDecimal(2);for (int i = 3; i <=N ; i++) {arr[i]=arr[i-1].add(arr[i-2]);}System.out.println(arr[N]);reader.close();}
}