QOJ.ac

QOJ

Time Limit: 1 s Memory Limit: 256 MB Total points: 100 Difficulty: [show]

#444. 算术表达式

統計

题目描述

我们如下定义表达式:

  • 一个在 $[0,M-1]$ 内且没有多余前导零的整数是一个表达式
  • 若 $E$ 是一个表达式,则 $(E)$ 是一个表达式
  • 若 $E_1,E_2$ 是一个表达式,则 $E_1+E_2$ 和 $E_1-E_2$ 都是表达式

现在给定 $N,M,P$,你需要求有多少个长度为 $N$ 的表达式满足它的值模 $M$ 等于 $P$

由于答案可能非常大,你只需要输出答案对 $10^9+7$ 取模后的值

输入格式

输入只有一行,包含三个整数 $N,M,P$。保证 $0 \leq M < P$。

输出格式

输出一行一个整数,表示答案。

样例数据

样例 1 输入

3 100 98

样例 1 输出

8

样例 2 输入

50 200 70

样例 2 输出

130371982

子任务

对于 $30\%$ 的数据,$N \leq 6$。

对于 $50\%$ 的数据,$N \leq 20, M \leq 50$。

另有 $20\%$ 的数据,$M = 2$。

对于 $100\%$ 的数据,$1 \leq N \leq 50, 1 \leq M \leq 200$。

Discussions

About Discussions

The discussion section is only for posting: Editorials, General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues. Submitting multiple issues may cause your account to be banned.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.