oppaiAnalysis

oppaiAnalysis.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OppaiAnalysis
{
    static class OppaiAnalysis
    {
        static public double Cup2Cm(string cup)
        {
            if (cup == "AAA") { return 5; }
            else if (cup == "AA") { return 7.5; }
            else if (cup == "ZZ") { return 75; }
            else if (cup == "ZZZ") { return 77.5; }
            
            return (Convert.ToInt32(cup.ToCharArray()[0]) - Convert.ToInt32('A'))*2.5 + 10;
        }

        static public string Cm2Cup(double cm)
        {
            if( cm <= 6.25) {return "AAA";}
            else if( cm <= 8.75){ return "AA";}
            else if ( cm >= 77.5) {return "ZZZ";}
            else if ( cm >= 75) { return "ZZ";}

            return (Convert.ToChar((int)(Math.Floor((cm - 10)/2.5) + 65))).ToString();
        }
    }
}

sample.cs

var realisticSize = OppaiAnalysis.Cup2Cm("C");
Console.WriteLine(realisticSize); // "15"
var worldRecord = OppaiAnalysis.Cm2Cup(102.5);
Console.WriteLine(worldRecord); // "ZZZ"