Alien Battle

A game to shoot down an alien

Developed by

Steve Musgrave

Technologies used

Technology	Used for
Ruby 2.2.0	Programming language
Rspec 3.1.7	Test Driven Development - unit testing

How to run the program:

From your terminal:

$ git clone [email protected]:StephanMusgrave/alien.git $ cd alien

To run the program from the command line:

$ ruby game.rb

To run the unit tests:

$ rspec

Fixed parameters:

Nozzle velocity: 50 m/s Step size for alien movement: 20 m Gravity: 9.81 m/s^2

Objective

There is a player with a spaceship at position 0 along an axis, and there is an alien at some unknown initial position x_0 on that axis.

The player and the (computer-controlled) alien take turns.

The player tries to hit the alien.

In each player turn the player can set the firing angle alpha of the spaceship and then fire it.

The nozzle velocity v of the spaceship is fixed.

The spaceship ball hits the ground at this distance x_impact from the spaceship: x_impact = (2cos(alpha)sin(alpha)v^2)/g where g = 9.81 m/s^2 is the earth's gravitational acceleration.

In each alien turn the alien moves one step (of some fixed size m) to the right or to the left with equal probability. The game goes on until the spaceship ball hits the ground within a distance d of the alien's current position.

Write a game that lets the user play until he hits the alien.

You can pick values for the fixed parameters in this problem.