AdventOfCode23/Day22/Vec.cs

namespace Day22;

public record struct Vec(long X, long Y, long Z)
{
    public static Vec Zero { get; } = new Vec(0, 0, 0);
    public static Vec Up { get; } = new Vec(0, 0, 1);
    public static Vec Down { get; } = new Vec(0, 0, -1);

    public static Vec FromArray(int[] nums)
    {
        return new Vec(nums[0], nums[1], nums[2]);
    }

    public Vec Add(Vec other)
    {
        return new Vec(X + other.X, Y + other.Y, Z + other.Z);
    }

    public Vec Subtract(Vec other)
    {
        return new Vec(X - other.X, Y - other.Y, Z - other.Z);
    }
    
    public long Magnitude()
    {
        if (new[] { X, Y, Z }.Count(v => v == 0) < 2)
        {
            throw new Exception("Only works with one-axis vectors");
        }
        return X + Y + Z;
    }

    public Vec Normalize()
    {
        var length = Magnitude();
        length = length == 0 ? 1 : length;
        return new Vec(X / length, Y / length, Z / length);
    }

    public Vec Multiply(long f)
    {
        return new Vec(f * X, f * Y, f * Z);
    }
}