GUIDELINES & RULES

The Objective

Tesseract’26 is a Reverse Coding challenge. Unlike standard competitive programming, you are not provided with a problem statement. Instead, you face a "Black Box", a compiled executable with hidden logic.

The Workflow

• 1
  ProbeAccess the specific challenge via the "SANDBOX" page. You will see an Input field.
• 2
  AnalyzeFeed inputs into the Black Box and observe the resulting Outputs.

  Example: Input 2 → Output 5; Input 3 → Output 10.
• 3
  DeduceUse inductive reasoning to determine the function f(x) or algorithm that transforms the Input to the Output.
• 4
  ImplementWrite a solution in C++, Java, or Python that replicates this logic.
• 5
  SubmitSubmit your source code to the corresponding problem on Codeforces.

Platform Architecture

A. Solution Integrity (The "No Hard-Coding" Rule)

• Generalization is Mandatory: Your code must implement the general algorithm/mathematical formula.
• Prohibited: "Hard-coding" solutions or using "Lookup Tables" (e.g., massive if-else chains or HashMaps mapping specific inputs to outputs) is strictly forbidden.
• Consequence: Even if a Lookup Table solution passes the Codeforces system tests, it will be disqualified during the manual code review phase.

B. Interface Usage

• Rate Limiting: The Black Box interface is rate-limited to prevent server overload. You may only execute 1 request every 2 seconds on the Sandbox. Automated scripts/bots designed to brute-force the input space (e.g., sending 1000 requests/second) will automatically be blocked by the system.
• Input Constraints: The Black Box on the website may handle smaller constraints (e.g., N ≤ 100) for demonstration. Note that constraints will be explicitly mentioned on the Black Box interface. The Codeforces system tests may test up to N ≤ 10⁹ or 10¹⁸. Your logic must hold for the larger constraints.

C. Competition Rules

• Individual Participation: This is a solo event. Collaboration, team-play, or sharing logic with other participants is prohibited.
• AI & Tools:
  • Use of standard IDEs and local documentation is allowed.
  • Use of Generative AI (ChatGPT, Gemini, etc.) to generate the code is prohibited.
  • Using automated tools to interact with the Codeforces judge is strictly prohibited.