https://github.com/sergeychelak/synacor_challenge

Completed Synacor Challenge
https://github.com/sergeychelak/synacor_challenge

backtracking backtracking-algorithm backtracking-search challenge memoization permutation-algorithms permutations rust synacor-challenge virtual-machine

Last synced: 3 days ago
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Completed Synacor Challenge

• Host: GitHub
• URL: https://github.com/sergeychelak/synacor_challenge
• Owner: SergeyChelak
• Created: 2022-11-02T20:39:52.000Z (about 2 years ago)
• Default Branch: master
• Last Pushed: 2022-11-13T16:23:56.000Z (about 2 years ago)
• Last Synced: 2023-04-25T21:49:10.314Z (over 1 year ago)
• Topics: backtracking, backtracking-algorithm, backtracking-search, challenge, memoization, permutation-algorithms, permutations, rust, synacor-challenge, virtual-machine
• Language: Rust
• Homepage:
• Size: 107 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# [Synacor Challenge](https://challenge.synacor.com)

This project is a usual CLI application written in Rust. It also contains additional folders:

- **data** contains the executable binary for Virtual Machine and script with the full list of commands to complete the challenge

- **playground** contains tiny CLI apps that were written during solving quest's tasks

## Virtual Machine

The whole challenge is messing around with a virtual machine. In the very beginning, you should implement 22 instructions according to the architecture specifications. That's not sound like a pretty complex task but it requires a accuracy in this routine.


Once the virtual machine is completed, you may start it and play the text-based adventure game. Hello from 80th)


## The Adventure Game

Make sure that Cargo and Rust are installed. Then execute in your command line

```

cargo run -- data/challenge.bin

```

## Coins

The bruteforce solution to order the coins is [here](https://github.com/SergeyChelak/virtual_machine/blob/master/playground/coins/main.rs)

## Teleporter

I needed to write a disassembly and execution dump for the virtual machine to obtain the entry point, conditions to activate the handheld teleporter, and bypass its confirmation mechanism. There is a separate [branch](https://github.com/SergeyChelak/virtual_machine/tree/disassembly) for that purpose. The result is looks something like this:

```

5483          set [r0] 4

5486          set [r1] 1

5489         call @6027

6027           jt [r0] @6035

6030          add [r0] [r1]  1

6034          ret

6035           jt [r1] @6048

6038          add [r0] [r0]  32767

6042          set [r1] [r7]

6045         call @6027

6047          ret

6048         push [r0]

6050          add [r1] [r1]  32767

6054         call @6027           

6056          set [r1] [r0]       

6059          pop [r0]

6061          add [r0] [r0]  32767

6065         call @6027           

6067          ret

```

The search for valid value for the 8th register is [here](https://github.com/SergeyChelak/virtual_machine/blob/master/playground/confirmation/main.rs). The virtual machine patches the program before execution to pass the confirmation mechanism and, of course, to obtain the valid next challenge code.


Actually, this is an [Ackermann function](https://en.wikipedia.org/wiki/Ackermann_function)

## Vault

You need to change the orb's weight from 22 to 30 by moving among the rooms. The path should be the shortest. The backtracking search for this task is [here](https://github.com/SergeyChelak/virtual_machine/blob/master/playground/vault/main.rs). It isn't a brilliant implementation but good enough to pass this task and complete the challenge.

## Whole challenge

This is a great spoiler on how to pass the challenge and obtain all codes (except the first one):

```

cargo run -- data/challenge.bin data/script.txt

```

Enjoy)