Codeforces Round #240 (Div. 1)B---Mashmokh and ACM(水dp)

最新推荐文章于 2024-05-31 15:26:09 发布

tokers

最新推荐文章于 2024-05-31 15:26:09 发布

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分类专栏： DP codeforces 文章标签： dp

本文链接：https://blog.youkuaiyun.com/Guard_Mine/article/details/44339945

这篇博客介绍了一个编程任务，要求找到所有长度为k且每个数字能被下一个数字整除的序列（好序列）。给定整数n和k，求解这类序列的数量，并对10^9 + 7取模。示例给出了不同n和k的解决方案数量。

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Mashmokh’s boss, Bimokh, didn’t like Mashmokh. So he fired him. Mashmokh decided to go to university and participate in ACM instead of finding a new job. He wants to become a member of Bamokh’s team. In order to join he was given some programming tasks and one week to solve them. Mashmokh is not a very experienced programmer. Actually he is not a programmer at all. So he wasn’t able to solve them. That’s why he asked you to help him with these tasks. One of these tasks is the following.

A sequence of l integers b1, b2, …, bl (1 ≤ b1 ≤ b2 ≤ … ≤ bl ≤ n) is called good if each number divides (without a remainder) by the next number in the sequence. More formally for all i (1 ≤ i ≤ l - 1).

Given n and k find the number of good sequences of length k. As the answer can be rather large print it modulo 1000000007 (109 + 7).
Input

The first line of input contains two space-separated integers n, k (1 ≤ n, k ≤ 2000).
Output

Output a single integer — th