C# “告诉”解决方案的目的是什么？做些调查，你会发现的！发现后，你永远不会忘记。有人告诉你，你在两周内记不起来了……谢谢，但我如何使用阵列来防止这种重复？@user3504400（假设这有点像真实的银行场景）你不需要这样做。两个人可以拥有相同的PIN码。但是如

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“告诉”解决方案的目的是什么？做些调查，你会发现的！发现后，你永远不会忘记。有人告诉你，你在两周内记不起来了……谢谢，但我如何使用阵列来防止这种重复？@user3504400（假设这有点像真实的银行场景）你不需要这样做。两个人可以拥有相同的PIN码。但是如果你随机生成它们，你不想给它们相同的PIN码。

class BankAccount
{
    private string firstName;
    private string lastName;
    private int accountNumber;
    private decimal balance;
    static public int customers = 0;
    private int pinNumber;

    public decimal Balance
    {
        get
        {
            return balance;
        }
        set
        {
            if (value >= 0)
                balance = value;
            else
            {
                Console.WriteLine("There will be an overdraft fee of $10.00.");
                balance = value - 10;
            }
        }
    }

    public string FirstName
    {
        get
        {
            return firstName;
        }
    }

    public string LastName
    {
        get
        {
            return lastName;
        }
    }

    public int AccountNumber
    {
        get
        {
            return accountNumber;
        }
    }

    public int PinNumber
    {
        get
        {
            return pinNumber;
        }
    }

    public BankAccount(string firstNameValue, string lastNameValue)
    {
        firstName = firstNameValue;
        lastName = lastNameValue;
        accountNumber = customers + 1;
        Random pin = new Random();
        pinNumber = pin.Next(1111, 9999);
        Balance = 0;
        customers++;
    }

    public BankAccount()
    {
        Balance = 0;
        customers++;
    }

    public void Credit(decimal amount)
    {
        Balance = Balance + amount;
    }

    public void Debit(decimal amount)
    {
        if (amount > Balance)
            Console.WriteLine("Debit amount exceeded account balance.");
        Balance = Balance - amount;
    }

    public static decimal AverageBalance(BankAccount[] accounts)
    {
        int count = 0;
        decimal total = 0;
        for (int i = 0; i < accounts.Length; i++)
        {
            if (accounts[i] != null)
            {
                total += accounts[i].Balance;
                count++;
            }
        }
        return total / count;
    }
}

static Random random = new Random();

// later, in the constructor
pinNumber = random.Next(0, 10000); // 0 <= pinNumber < 10000

public void SetValues(int[] array)
    {
        Random randomNumber = new Random();

        for (int i = 0; i < array.Length; i++)
        {
            bool distinctNumber = true;
            int number = randomNumber.Next(1, 100);
            for (int j = 0; j < i; j++)
            {
                if (number == array[j])
                {
                    distinctNumber = false;
                    break;
                }
            }
            if ( distinctNumber )      
                array[i] = number;
            else
                --i;    
        }
    }

Random rnd = new Random();

var pin = new[] {-1, -1, -1, -1};

for(var i = 0; i < pin.length; i++)
   int nextDigit = rnd.Next(0, 10);
   while (pin.contains(nextDigit)){ nextDigit + rnd.Next(0, 10); }
   pin[i] = nextDigit;
}

public static void Shuffle<T>(this IList<T> list)  
{  
    Random rng = new Random();  
    int n = list.Count;  
    while (n > 1) {  
        n--;  
        int k = rng.Next(n + 1);  
        T value = list[k];  
        list[k] = list[n];  
        list[n] = value;  
    }  
}

    var pinDigits = new List<int>(Enumerable.Range(0,10));
    pinDigits.Shuffle();
    return pinDigits.Take(4);

public static IEnumerable<T> GeneratePIN<T>(IEnumerable<T> valueRange, int length)
{
    var pinValues = new List<T>(valueRange);
    pinValues.Shuffle();
    return pinValues.Take(length);
}