particleSim.cs

using System;
using System.Collections.Generic;

abstract class Particle {
    public String name;
    public List<float> position;
    public List<float> color;

    public abstract float positionMassFreqValue(int i);
    public abstract void update(Particle other);
}

class HeavyParticle : Particle {
    public float mass;

    public override float positionMassFreqValue(int i) {
        return position[i] * mass;
    }

    public override void update(Particle other) {
        for (int i = 0; i < position.Count; ++i) {
            position[i] = other.positionMassFreqValue(i) - positionMassFreqValue(i);
        }
    }
}

class LightParticle : Particle {
    public float frequency;
    public float brightness;

    public override float positionMassFreqValue(int i) {
        return position[i] * frequency * brightness;
    }

    public override void update(Particle other) {
        for (int i = 0; i < position.Count; ++i) {
            position[i] = other.positionMassFreqValue(i) + positionMassFreqValue(i);
        }
    }
}

class HelloWorld {
    static void Main() {
        List<Particle> particles = new List<Particle>();

        int particleCount = 1000;
        int iterationCount = 1000;

        // Init
        for (int i = 0; i < particleCount; ++i) {
            List<float> particlePosition = new List<float>();
            particlePosition.Add(i * 1.0f);
            particlePosition.Add(i + 1.0f);

            List<float> particleColor = new List<float>();
            particleColor.Add(1.0f);
            particleColor.Add(1.0f);
            particleColor.Add(1.0f);

            String particleName = "Particle" + i;

            if (i % 2 == 0) {
                particles.Add(new HeavyParticle() { 
                    position = particlePosition,
                    color = particleColor,
                    name = particleName,
                    mass = i * 100.0f,
                });
            } else {
                particles.Add(new LightParticle() { 
                    position = particlePosition,
                    color = particleColor,
                    name = particleName,
                    frequency = i / 100.0f,
                    brightness = i * 12.0f,
                });
            }
        }

        for (int i = 0; i < iterationCount; ++i) {
            // Main each-to-each simulation loop 
            for (int a = 0; a < particles.Count; ++a) {
                for (int b = a + 1; b < particles.Count; ++b) {
                    particles[a].update(particles[b]);
                }
            }

            // Bounding conditions so that we don't NaN :P
            for (int a = 0; a < particles.Count; ++a) {
                if (particles[a].position[0] > 10000) {
                    particles[a].position[0] = 10000;
                }
                if (particles[a].position[0] < -10000) {
                    particles[a].position[0] = -10000;
                }
                if (particles[a].position[1] > 10000) {
                    particles[a].position[1] = 10000;
                }
                if (particles[a].position[1] < -10000) {
                    particles[a].position[1] = -10000;
                }
            }
        }

        // Some very basic "result" output
        float avg_x = 0.0f;
        float avg_y = 0.0f;

        for (int i = 0; i < particles.Count; ++i) {
            avg_x += particles[i].position[0];
            avg_y += particles[i].position[1];
        }

        System.Console.WriteLine(avg_x + ", " + avg_y);
    }
}