如何在C#彩票程序中防止重复输入相同数字？

你的程序已实现数字范围校验，但缺少重复输入的检查逻辑。只需在确认输入数字合法（1-25）后，检查该数字是否已存在于之前输入的数组元素中，即可解决问题。以下是修改后的完整代码：

Console.ForegroundColor = ConsoleColor.DarkYellow;
Console.Clear();
Console.WriteLine("Welcome to the lottery!");

static int GetGuess()
{
    int guess = 0;
    bool ok = false;

    while(!ok)
    {
        Console.ForegroundColor= ConsoleColor.DarkYellow;
        Console.WriteLine("Type in a number between 1 and 25");
        Console.ResetColor();
        ok = int.TryParse(Console.ReadLine(), out guess);

        if(!ok)
        {
            Console.ForegroundColor= ConsoleColor.DarkYellow;
            Console.WriteLine("Inaccurate input");
        }
    }

    return guess;
}

int[] myArray = new int[5];
int guess;

for (int i = 0; i < myArray.Length; i++)
{
    guess = GetGuess();

    // 先检查数字范围合法性
    if(guess > 0 && guess < 26)
    {
        bool isDuplicate = false;
        // 遍历已输入的数组元素，检查是否重复
        for (int j = 0; j < i; j++)
        {
            if (myArray[j] == guess)
            {
                isDuplicate = true;
                break;
            }
        }

        if (!isDuplicate)
        {
            myArray[i] = guess;
        }
        else
        {
            Console.ForegroundColor= ConsoleColor.Red;
            Console.WriteLine("You've already entered this number, please input a new one!");
            i--; // 停留在当前索引，让用户重新输入
        }
    }
    else
    {
        Console.ForegroundColor= ConsoleColor.Red;
        Console.WriteLine("You didn't enter a number between 1 and 25");
        i--;
    }

}

foreach (int i in myArray)
    Console.Write(i + " ");

Random rnd = new Random();
int dragning = rnd.Next(1, 26);
int rightAnswerAmount = 0;

foreach(int i in myArray)
{
    if (i == dragning)
        rightAnswerAmount++;
}

Console.ForegroundColor= ConsoleColor.Green;

if (rightAnswerAmount> 0)
    Console.WriteLine("\nCongratz! You had {0} amount of wins!", rightAnswerAmount);
else
    Console.WriteLine("\nYou lost all your money");

关键修改说明 #

1. 新增isDuplicate标记，用于判断当前输入是否与已输入数字重复
2. 通过内层循环遍历数组中已填充的元素（索引0到i-1），对比当前输入值
3. 若检测到重复，提示用户重新输入，并通过i--让外层循环停留在当前索引，确保用户重新填写该位置的数字
4. 优化结果输出的换行格式，提升可读性

内容的提问来源于stack exchange，提问作者Karin Wilson