将月份转换为等效于快速排序的数字

Question

我有几个月从外部文本文件读入一个数组，我需要将月份转换为一个数组，该数组包含与月份等价的值，例如一月 = 1，二月 = 2 等等。这样他们就可以通过快速排序。

 public static void Main(string[] args)
    {
        //Read external files into arrays.
        string[] Month = File.ReadLines(@"Month.txt").ToArray();
        string[] Year = File.ReadLines(@"Year.txt").ToArray();

        //Convert arrays from string to double to be used in sort.
        double[] YearSort = Array.ConvertAll(Year, double.Parse);

        int UserInput1;

        //Create new array that will hold selected array to be used in sort. 
        double[] data = new double[1022];
        //Prompt user to select action. 
    Console.WriteLine("Press 1 to Sort by month or 2 to sort by year.");
     UserInput1 = Convert.ToInt32(Console.ReadLine());

    if(UserInput1 == 1)
    {
        Array.Copy(Month,data,1022);
        QuickSort(data); 
         for (int i = 0; i < 1022; i++)
  Console.WriteLine(data[i]);
  Console.WriteLine();
    }
    else if (UserInput1 == 2)
    {
        Array.Copy(YearSort,data,1022);
        QuickSort(data); 
         for (int i = 0; i < 1022; i++)
  Console.WriteLine(data[i]);
  Console.WriteLine();
    }
    else
    {
        Console.WriteLine("Please try again and select a valid option");
    }
    }

static int MonthToDouble( string Month )
        {
            int NewMonth = 0;

            switch(Month)
            {
                case "January":
                case "january":
                    NewMonth = 1;
                    break;
                case "February":
                case "february":
                    NewMonth = 2;
                    break;
                case "March":
                case "march":
                    NewMonth = 3;
                    break;
                case "April":
                case "april":
                    NewMonth = 4;
                    break;
                case "May":
                case "may":
                    NewMonth = 5;
                    break;
                case "June":
                case "june":
                    NewMonth = 6;
                    break;
                case "July":
                case "july":
                    NewMonth = 7;
                    break;
                case "August":
                case "august":
                    NewMonth = 8;
                    break;
                case "September":
                case "september":
                    NewMonth = 9;
                    break;
                case "October":
                case "october":
                    NewMonth = 10;
                    break;
                case "November":
                case "november":
                    NewMonth = 11;
                    break;
                case "December":
                case "december":
                    NewMonth = 12;
                    break;
            }

            return NewMonth;
        }

        static string DoubleToMonth(double Month)
        {
            string NewMonth = "";

            switch ((int)Month) 
            {
                case 1:
                    NewMonth = "January";
                    break;
                case 2:
                    NewMonth = "February";
                    break;
                case 3:
                    NewMonth = "March";
                    break;
                case 4:
                    NewMonth = "April";
                    break;
                case 5:
                    NewMonth = "May";
                    break;
                case 6:
                    NewMonth = "June";
                    break;
                case 7:
                    NewMonth = "July";
                    break;
                case 8:
                    NewMonth = "August";
                    break;
                case 9:
                    NewMonth = "September";
                    break;
                case 10:
                    NewMonth = "October";
                    break;
                case 11:
                    NewMonth = "November";
                    break;
                case 12:
                    NewMonth = "December";
                    break;
            }

            return NewMonth;
        }

 //QuickSort for double data values are in ascending order. 
 public static void QuickSort(double[] data)
 {
 Quick_Sort(data, 0, data.Length - 1);
 }
public static void Quick_Sort(double[] data, int left, int right)
 {
 int i, j;
 double pivot, temp;
 i = left;
 j = right;
 pivot = data[(left + right) / 2];
 do
 {
 while ((data[i] < pivot) && (i < right)) i++;
 while ((pivot < data[j]) && (j > left)) j--;
 if (i <= j)
 {
 temp = data[i];
data[i] = data[j];
data[j] = temp;
i++;
j--;
 }
 } while (i <= j);
 if (left < j) Quick_Sort(data, left, j);
 if (i < right) Quick_Sort(data, i, right);
 }          
}

Answer 1

ADateTimeobject的Month property gives you the integer value of the month starting at 1 like you need. So you can use DateTime.ParseExact()把字符串解析成完整的DateTimeobject然后抓取Month属性:

int monthNumber = DateTime.ParseExact("January", "MMMM", CultureInfo.CurrentCulture).Month;

您只需将 "January" 替换为您的月份字符串，并保留 "MMMM"，即 "The full name of the month" 的 Custom Format String。

以上代码所做的只是简化你的 MonthToDouble() 方法，你出于某种原因甚至没有使用它（它应该 return 一个 double，而不是 int).与您的标题相反，您已经有了 "Convert months to number equivalent" 的方法，只是您没有使用它。

所以，我想你唯一缺少的就是替换这个：

    Array.Copy(Month,data,1022);
    QuickSort(data);

有了这个：

        double[] monthsAsDoubles = new double[Month.Length];
        for (int i = 0; i < monthsAsDoubles.Length; i++)
        {
            monthsAsDoubles[i] = MonthToDouble(Month[i]);
        }
        QuickSort(monthsAsDoubles);

同时将 MonthToDouble() 的 return 值从 int 更改为 double（如果需要则进行转换）。

Answer 2

编辑： 仔细想想，Quantic 的答案更简单。我将把它留在这里作为替代。

通过使用 DateTimeFormatInfo.MonthNames 属性以及不区分大小写的字符串比较，您的代码可以大大简化。这也有更容易移植以使用不同语言的月份名称的优势。

这是一个片段：

using System;
using System.Globalization;
using System.Linq;
using System.Collections.Generic;

public class Test
{
    public static void Main()
    {

        var InputMonths = new List<string> { "January","march","sepTEmber","smarch" };

        var MonthNames = new DateTimeFormatInfo().MonthNames.ToList();

        var InputMonthNumbers = new List<int>();

        foreach (var m in InputMonths)
        {
            //Find index of the month name, ignoring case
            //Note if the input month name is invalid, FindIndex will return 0
            int month_num = 1 + MonthNames.FindIndex(name => name.Equals(m, StringComparison.OrdinalIgnoreCase));

            if (month_num > 0)
            {
                InputMonthNumbers.Add(month_num);
            }
        }

        foreach (var n in InputMonthNumbers)
        {
            Console.WriteLine(n.ToString());
        }

    }
}

输出：

1
3
9

将月份转换为等效于快速排序的数字

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