遍历列表以检查数字是否连续

Question

代码的目标是获取一串由连字符分隔的数字，并检查它们是否连续。我尝试使用 string.spit，遍历数组并检查数字 +1 是否等于下一个值。但是我运行遇到了我正在处理的索引超出数组边界的问题。这是当前版本。

public static void Consecutive()
    {
        Console.Write("enter multiple numbers separated by hyphens: ");
        var userinput = Console.ReadLine();
        
        var nums = userinput.Split();
        
        int index = 0;
        bool isConsecutive = false;

        foreach(var number in nums)
        {
            if(Convert.ToInt32(nums[index + 1]) == Convert.ToInt32(nums[index] + 1))
            {
                isConsecutive = true;
            }
            else
            {
                isConsecutive = false;
            }
            if(index == nums.Length)
            {
                break;
            }
        }
        Console.WriteLine(isConsecutive);
    }

Answer 1

这是因为当 foreach 循环遍历最后一个元素时，没有包含 index + 1 的元素，并且您的检查 if(index == nums.Length) 不起作用。

解释：

nums.Length = 最后一个索引 + 1.

对于包含 5 个元素的数组，长度 = 5，最后一个索引 = 4。

因为你的 if 条件永远不会 true.

解法：

将条件从 if(index == nums.Length) 更改为 if(index == nums.Length - 1)

Answer 2

您想按连字符拆分，但您按 white-spaces 拆分。您也不要使用 foreach 的 number 循环变量。对于你正在做的事情，for-loop 无论如何更合适：

public static void Consecutive()
{
    Console.WriteLine("enter multiple numbers separated by hyphens: ");
    string userinput = Console.ReadLine();
    string[] nums = userinput.Split('-');
    // always validate input
    while (!nums.All(n => n.All(char.IsDigit)))
    {
        Console.WriteLine("All numbers must be valid integers");
        userinput = Console.ReadLine();
        nums = userinput.Split('-');
    }

    bool isConsecutive = true;
    for(int i = 1; i < nums.Length; i++)
    {
        int thisInt = int.Parse(nums[i]);
        int prevInt = int.Parse(nums[i - 1]);
        if(thisInt != prevInt + 1)
        {
            isConsecutive = false;
            break;
        }
    }
    Console.WriteLine(isConsecutive);
}

Answer 3

这是一种不同的方法，生成预期的序列并查看它是否与清理后的输入匹配：

var delimiter = ",";
Console.Write("Enter multiple integers separated by '" + delimiter + "': ");
var userinput = Console.ReadLine(); ;

bool isConsecutive = false;
try
{
    var strNums = userinput.Split(delimiter.ToCharArray());
    var nums = Array.ConvertAll(strNums, x => int.Parse(x));
    var consecutive = Enumerable.Range(nums[0], nums.Length);

    var strCleansed = String.Join(delimiter, nums);
    var strGenerated = String.Join(delimiter, consecutive);
    isConsecutive = (strCleansed == strGenerated);

    Console.WriteLine("    cleansed = " + strCleansed);
    Console.WriteLine("   generated = " + strGenerated);
}
catch (Exception)
{
    Console.WriteLine("Invalid Integer in Input");
}

Console.WriteLine("isConsecutive = " + isConsecutive);
Console.ReadKey();

样本运行：

Enter multiple integers separated by ',': -3, -0000002,         -1,       0, 1, 02,   3
    cleansed = -3,-2,-1,0,1,2,3
   generated = -3,-2,-1,0,1,2,3
isConsecutive = True

Enter multiple integers separated by ',': 1,2,3,5
    cleansed = 1,2,3,5
   generated = 1,2,3,4
isConsecutive = False

Enter multiple integers separated by ',': 1,fish,2,fish,red fish,blue fish
Invalid Integer in Input
isConsecutive = False

遍历列表以检查数字是否连续

Iterating over a list to check if numbers are consecutive

c#

console