Zombie Apocalypse

This program was inspired by a zombie apocalypse problem statement created by Johni. His original intent was to use the scenario as the basis for playing with golang's concurrent concepts and primitives.

In Johni's conception, zombies use 1 of 4 different types of weapons and there are 4 heroes who are supposed to defeat the invading zombies. Each hero specializes in one kind of zombie weapon, meaning they will only fight those carrying the appropriate weapons.

Zombie weapons vs. heroes

Zombie weapon	Hero
Baseball bat	Tex Willer
Hatchet	Kit Carson
Scythe	Jack Tiger
Machete	Kit Willer

Adaptations

In the original design, channels were used to represent each type of zombie and their respective weapon. In other words, if a hatchet-carrying zombie was spawned, it would be sent to the hatchet channel. The receiving end would then assign the zombie to the corresponding hero, since it would know its weapon type.

In the present design, there are 2 different types of channels:

• ZombieChannel: as random zombies as generated, they are sent to one of 4 zombie channels, each representing the general direction from which a zombie spawned (north, south, east or west).
• HeroChannel: every time a new zombie arrives, it is directed to a hero channel, according to their type (the weapon they carry). There are a total of 4 hero channels (see table above).
• Technically, there's a third type of channel that is used for controlling the termination of the simulation.

General requirements and notes

• The number of zombies spawning from each direction is currently set in code.
• Zombie names are of the form D-NNNNN, where D represents the source direction and NNNNN is a sequential number. E.g. the third zombie coming from the west will be named W-00003.
• There should be a random delay between spawns.
• Heroes can only fight one zombie at a time.
• The hero channels are buffered and currently can hold up to 5 zombies. If the zombie spawn rate is much higher than the time needed for a hero to defeat a zombie, blocking will occur and the simulation will last longer. Anyway, the fact is that zombies will be waiting in line before they are confronted by their respective hero. Yes, not very exciting, but that's how it is for now.
• The simulation log includes 3 types of events: SPAWN, FIGHT and KILL.
• All simulations should start with one or more SPAWN events.
• Ideally, simulations should end with a KILL event. However, it might be possible that the timeout since last spawn is reached before all existing zombies have been defeated.

Improvement ideas

• External configuration of the simulation parameters.
  • Zombie spawn rate
  • Number of zombies spawning from each direction
  • Timeout from last spawn before the simulation is terminated.
• Statistics summary at the end of simulations.

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Andre Zunino <neyzunino@gmail.com>
October 2020