QOJ.ac

QOJ

実行時間制限: 2.0 s メモリ制限: 1024 MB 満点: 100 ハック可能 ✓

#15032. 密碼系統

統計

Alice 設計咗一個密碼系統:佢將明文編碼為一個 64 位無符號整數 $x$,並隨機揀一個 64 位無符號整數 $a$ 作為公開金鑰,將明文加密得到密文 $b = a^x \bmod 2^{64}$。特別地,定義 $0^0 = 1$。

而家,Bob 截獲咗 $n$ 組加密資訊 $(a_i, b_i)$($i = 1, 2, \dots, n$)。為咗解密所有資訊,Bob 需要對每組加密資訊,搵出最細嘅整數 $x_i$($0 \le x_i < 2^{64}$),使得 $a_i^{x_i} \equiv b_i \pmod{2^{64}}$,或者確定呢組資訊已經損壞(即係唔存在滿足條件嘅 $x_i$)。請寫一個程式幫 Bob 完成呢個任務。

輸入格式

輸入嘅第一行包含一個整數 $n$($1 \le n \le 10^5$),代表資訊嘅數量。

接落嚟嘅 $n$ 行,第 $i$ 行包含兩個整數 $a_i$ 同 $b_i$($0 \le a_i, b_i < 2^{64}$),分別代表第 $i$ 組資訊嘅公開金鑰同密文。

輸出格式

輸出 $n$ 行,對於第 $i$ 行:

  • 如果存在至少一個滿足題目條件嘅 $x_i$,輸出當中嘅最細值;
  • 否則,輸出一行 broken message。

範例

輸入

5
2 4
3 27
1000000007 998244353
4 2
1000000007 1000000009

輸出

2
3
994996658310742016
broken message
broken message

Editorials

IDTypeStatusTitlePosted ByLast UpdatedActions
#3008EditorialOpen题解KobicGendView
#904EditorialOpenNew Editorial for Problem #15032KiharaToumaView

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.