using System; using System.Collections.Generic; using System.Linq; // https://www.sololearn.com/Discuss/729355/?ref=app // https://www.freecodecamp.org/challenges/exact-change namespace SoloLearn { class Program { enum Denomination { Penny, Nickel, Dime, Quarter, One, Five, Ten, Twenty, OneHundred } static readonly Dictionary CashValue = new Dictionary { { Denomination.Penny, 0.01m }, { Denomination.Nickel, 0.05m }, { Denomination.Dime, 0.10m }, { Denomination.Quarter, 0.25m }, { Denomination.One, 1m }, { Denomination.Five, 5m }, { Denomination.Ten, 10m }, { Denomination.Twenty, 20m }, { Denomination.OneHundred, 100m } }; static void Main(string[] zephyr_koo) { Console.Write("Case 1: "); Console.WriteLine(CheckCashRegister(3.26m, 100m, new Dictionary { { Denomination.Penny, 1.01m }, { Denomination.Nickel, 2.05m }, { Denomination.Dime, 3.10m }, { Denomination.Quarter, 4.25m }, { Denomination.One, 90m }, { Denomination.Five, 55m }, { Denomination.Ten, 20m }, { Denomination.Twenty, 60m }, { Denomination.OneHundred, 100m } })); Console.Write("Case 2: "); Console.WriteLine(CheckCashRegister(19.50m, 20m, new Dictionary { { Denomination.Penny, 0.01m }, { Denomination.Nickel, 0 }, { Denomination.Dime, 0 }, { Denomination.Quarter, 0 }, { Denomination.One, 1m }, { Denomination.Five, 0 }, { Denomination.Ten, 0 }, { Denomination.Twenty, 0 }, { Denomination.OneHundred, 0 } })); Console.Write("Case 3: "); Console.WriteLine(CheckCashRegister(19.50m, 20m, new Dictionary { { Denomination.Penny, 0.50m }, { Denomination.Nickel, 0 }, { Denomination.Dime, 0 }, { Denomination.Quarter, 0 }, { Denomination.One, 0 }, { Denomination.Five, 0 }, { Denomination.Ten, 0 }, { Denomination.Twenty, 0 }, { Denomination.OneHundred, 0 } })); } static string CheckCashRegister(decimal itemPrice, decimal cash, Dictionary cashInDrawer) { var changeAmount = cash - itemPrice; var changeDue = new List> { PayoutChange(changeAmount, Denomination.OneHundred, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Twenty, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Ten, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Five, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.One, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Quarter, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Dime, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Nickel, cashInDrawer, out changeAmount), PayoutChange(changeAmount, Denomination.Penny, cashInDrawer, out changeAmount) }; return changeAmount != 0 ? // failed to fully pay the changeAmount? "Insufficient Funds" : cashInDrawer.Sum(c => c.Value) == 0 ? // any remaining cash in drawer? "Closed" : string.Join(", ", changeDue.Where(c => c.Value != 0)); } static KeyValuePair PayoutChange( decimal changeAmount, Denomination denomination, Dictionary cashInDrawer, out decimal remainingChange) { remainingChange = changeAmount; if (CashValue[denomination] > changeAmount) return new KeyValuePair(denomination, 0); var quantity = Math.Floor(changeAmount / CashValue[denomination]); var cashValue = Math.Min(quantity * CashValue[denomination], cashInDrawer[denomination]); cashInDrawer[denomination] -= cashValue; remainingChange = changeAmount - cashValue; return new KeyValuePair(denomination, cashValue); } } }

Cash Register Challenge (freeCodeCamp)