AdventOfCode23/Day19/Range.cs

namespace Day19;

public record Range(int Start, int End)
{
    public static Range Empty = new Range(-1, -1);

    public long Size => this == Empty ? 0 : (End - Start + 1);
    
    public Range LessThan(int value)
    {
        if (value <= Start)
        {
            return Empty;
        }

        if (value > End)
        {
            return this;
        }

        return this with { End = value - 1 };
    }

    public Range GreaterThan(int value)
    {
        if (value >= End)
        {
            return Empty;
        }

        if (value < Start)
        {
            return this;
        }

        return this with { Start = value + 1 };
    }
    
    public override string ToString()
    {
        return $"{Start} - {End}";
    }
}