QOJ.ac

QOJ

时间限制: 7 s 内存限制: 512 MB 总分: 100

#2835. 数论

统计

令 $o_i = \underbrace{1 \dots 1}_{i \text{ times}}$ 为十进制表示中由 $i$ 个 $1$ 组成的数。 Bobo 有一个整数 $n$。请找出一个可能包含负整数的序列 $(x_1, x_2, \dots)$,使得: $\sum_{i=1}^{\infty} o_i \cdot x_i = n$ $\sum_{i=1}^{\infty} i \cdot |x_i|$ 最小化。

输入格式

输入包含多组测试数据,以文件结束符(EOF)结束。对于每组测试数据: 第一行包含一个整数 $n$。 $1 \le n < 10^{5000}$ 对于所有输入, $n$ 的十进制位数之和不超过 $50000$。

输出格式

对于每组测试数据,输出一个整数,表示 $\sum_{i=1}^{\infty} i \cdot |x_i|$ 的最小值。

样例

样例输入 1

12
100
998244353

样例输出 1

3
5
76

说明

对于第一组测试数据,$x_1 = 1, x_2 = 1, x_3 = x_4 = \dots = 0$。最小值为 $1 \times 1 + 2 \times 1 = 3$。 对于第二组测试数据,$x_1 = 0, x_2 = -1, x_3 = 1, x_4 = x_5 = \dots = 0$。最小值为 $2 \times 1 + 3 \times 1 = 5$。

Editorials

IDTypeStatusTitlePosted ByLast UpdatedActions
#1352EditorialOpenNew Editorial for Problem #2835ZnPdCo2026-03-30 20:47:11View

Discussions

About Discussions

The discussion section is only for posting: 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.
  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.