同和创作矩阵 › ›博文归档› 技术博文归档 › 查看内容

22330_Tightwords

2022-5-16 18:21| 发布者: Hocassian| 查看: 21| 评论: 0|原作者: 肇庆学院ACM合集

摘要:

C:\Users\Administrator\Downloads\2019-10-12-10-14-5-89506328652700-Problem List-采集的数据-后羿采集器.html

Pro.ID

22330

Title

Tight words

Title链接

http://10.20.2.8/oj/exercise/problem?problem_id=22330

AC

Submit

Ratio

100.00%

时间&空间限制

Time Limit: 1000/500 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)

描述

Given is an alphabet { 0, 1, ... , k }, 0 ≤ k ≤ 9 . We say that a word of length n over this alphabet is tight if any two neighbour digits in the word do not differ by more than 1.

输入

Input is a sequence of lines, each line contains two integer numbers k and n, 1 ≤ n ≤ 100.

输出

Description

Given is an alphabet { 0, 1, ... , k }, 0 ≤ k ≤ 9 . We say that a word of length n over this alphabet is tight if any two neighbour digits in the word do not differ by more than 1.

Input

Input is a sequence of lines, each line contains two integer numbers k and n, 1 ≤ n ≤ 100.

Output

For each line of input, output the percentage of tight words of length n over the alphabet { 0, 1, ... , k } with 5 fractional digits.

Sample Input

4 1
2 5
3 5
8 7

Sample Output

100.00000
40.74074
17.38281
0.10130

Source

Waterloo local contest 2001