dospore / fighting-ants

A take home

Fighting Ants

Full description of the task.

General implemntation idea

Basic notes taken during development.

Initial thoughts

• want to use mappings to have quick lookups as well as O(1) add or removals at a specific index of Colonies or Ants
• ants dont belong to colonies they just freeroam so dont need to assign them any information besides their current location
• easiest to just use index number for ants id
• ants also want O(1) removal at index
• ants might get stranded on land and land might lose all of its neighbours this is ok
• when removing a Colony after a war their will be a floating connection unless you clean up the ants previous locations
• more than 1 ant can move to the same Colony (more of an assumption) but just going to assume there can also be more than 1 ant involved in a war

Steps;

1. Construct world The world will contain a mapping from Colony -> ColonyState as well as a list of Ants

    type Colony = string

    type ColonyState = {
        north: string | undefined,
        south: string | undefined,
        east: string | undefined,
        west: string | undefined,
    }

    type Ant = {
        location: Colony
    }

    type World {
        state: Map<Colony, ColonyState>,
        ants: Ant[]
    }

2. Each round will move the ants randomly. Available directions are non undefined values, as well truthy values for state.get(direction) (this avoids taking the path to a dangling Colony). Move an ant, when more than one ant is marked at a location we will remove that location from the World.state // no need to follow the paths back to the ants previous location since we can just remove once we get to it in cleanup / write stage // This approach has a worse time complexity since at the end I have to loop through M remaining colonies and clean them

3. Continue step two until all the ants are dead or there have been 10k iterations

4. Print out the remaining state of the world // remember to clean up the dangling Colonies if not done in step 2

TS Solution

// install packages
yarn install

// run simulation
yarn simulate <NUM_ANTS> <WORLD_FILE_PATH>

// eg
yarn simulate 100 ./worlds/hiveum_map_medium.txt

Remaining output of world gets sent to ./worlds/remainder.txt

RS Solution

cargo run --manifest-path="./rs/Cargo.toml" <NUM_ANTS> <WORLD_FILE_PATH>
// eg
cargo run --manifest-path=\"./rs/Cargo.toml\" 100 ./worlds/hiveum_map_small.txt

// or 
yarn simulate-rs <NUM_ANTS> <WORLD_FILE_PATH>
// eg
yarn simulate-rs 100 ./worlds/hiveum_map_small.txt

Assumptions

Input file

• north/south/east/west are space seperated
• no directions exist outside of north/south/east/west

World Generation

• Ants are placed randomly amongst the colonies and can start in the same colony
• More than one ant can start in the same place, they dont kill eachother straight away
• There are no Ant teams, they fight for themselves, they have no loyalty
• Isolated colonies are fine