按字典顺序比较两个 char 数组

Question

你能帮忙吗？

I need to compare lexicographically two arrays: if one of them is shorter than other, it is lexicographically first. If their length are same, they had to be compared element by element. If an element is before the other in the alphabet, this array is lexicographically first.

这是我的代码：

using System;

internal class CompareTwoCharArraysLexicographically
{
    private static void Main()
    {
       char[] firstArray = {'a', 'b', 'c', 'z'};
       int firstArrayLength = firstArray.Length;
       char[] secondArray = {'a', 'b', 'c', 'd'};
       int secondArrayLength = secondArray.Length;
       int length = Math.Min(firstArray.Length, secondArray.Length);

       if (firstArray.Length > secondArray.Length)
       {
          Console.WriteLine("Second array is earlier.");
       }

       else if (firstArray.Length == secondArray.Length)
       {
          for (int i = 0; i < length; i++)
          {
              if (firstArray[i] > secondArray[i])
              {
                  Console.WriteLine("2 array is earlier.");
                  break;
              }
              else if (secondArray[i] > firstArray[i])
              {
                  Console.WriteLine("1 array is earlier."); 
                  break;
              }
              else
              {
                  Console.WriteLine("Two arrays are equal.");
              }
          }
       }
       else
       {
          Console.WriteLine("First array is earlier.");
       }
    }
}

如何避免三次重复消息"Two arrays are equal."？

Answer 1

我认为您需要使用跟踪变量来了解数组是否相等。目前，您是说每次同一索引中的两个项目相等时它们就相等。相反，请考虑以下代码：

else if (firstArray.Length == secondArray.Length)
{
    var largerArray = 0;

    // Compare each item in the array
    for (int i = 0; i < length; i++)
    {
        // As soon as two items are not equal, set the comparison value and break
        if (firstArray[i] > secondArray[i])
        {
            largerArray = 1;
            break;
        }
        else if (secondArray[i] > firstArray[i])
        {
            largerArray = 2
            break;
        }
    }

    // Check the largerArray value. If it was never changed, the arrays are equal
    // Otherwise, display a message based on the value of the largerArray.
    if (largerArray == 0)
    {
        Console.WriteLine("Two arrays are equal.");
    }
    else
    {
        Console.WriteLine("{0} array is earlier.", largerArray); 
    }
}

Answer 2

另一种结构化的方法：

class LexicographicCharArrayComparer : Comparer<char[]>
{
    public override int Compare(char[] x, char[] y)
    {
        if (x == null || y == null)
            return Default.Compare(x, y);

        int lengthComp = x.Length.CompareTo(y.Length);
        if (lengthComp != 0)
            return lengthComp;

        return StringComparer.Ordinal.Compare(new string(x), new string(y));
    }
}

用法：

        char[] firstArray = { 'a', 'b', 'c', 'z', };
        char[] secondArray = { 'a', 'b', 'c', 'd', };

        var comparer = new LexicographicCharArrayComparer();
        var result = comparer.Compare(firstArray, secondArray);
        if (result < 0)
            Console.WriteLine("1st array is earlier");
        else if (result == 0)
            Console.WriteLine("The two arrays are equal");
        else
            Console.WriteLine("2nd array is earlier");

你自己的方法当然是可以修复的。将中间块更正为：

   else if (firstArray.Length == secondArray.Length)
   {
      bool resolved = false;
      for (int i = 0; i < length; i++)
      {
          if (firstArray[i] > secondArray[i])
          {
              Console.WriteLine("2 array is earlier.");
              resolved = true;
              break;
          }
          if (secondArray[i] > firstArray[i])
          {
              Console.WriteLine("1 array is earlier."); 
              resolved = true;
              break;
          }
      }
      if (!resolved)
      {
          Console.WriteLine("Two arrays are equal.");
      }
   }

Answer 3

这是我的建议：

        Console.Write("Enter a positive number for length of the first array: ");
        int n = int.Parse(Console.ReadLine());
        Console.Write("Enter a positive number for length of the second array: ");
        int m = int.Parse(Console.ReadLine());

        // Declare and create the arrays
        char[] firstArray = new char[n];
        char[] secondArray = new char[m];

        Console.WriteLine("Enter values of the arrays: ");
        for (int i = 0; i <  firstArray.Length; i++)
        {
            firstArray[i] = char.Parse(Console.ReadLine());
        }
        Console.WriteLine();

        for (int i = 0; i < m; i++)
        {
            secondArray[i] = char.Parse(Console.ReadLine());
        }
        Console.WriteLine();

        // Print them on the console
        for (int i = 0; i < n; i++)
        {
            Console.Write(" " + firstArray[i]);
        }            
        Console.WriteLine();

        for (int i = 0; i < m; i++)
        {
            Console.Write(" " + secondArray[i]);
        }            
        Console.WriteLine();

        int minLength = Math.Min(firstArray.Length, secondArray.Length);
        bool equalValues = true;

        // Search which of the arrays is lexicographically earlier
            for (int i = 0; i < minLength; i++)
            {
                if (firstArray[i] == secondArray[i])
                {
                    continue;
                }
                else if (firstArray[i] < secondArray[i])
                {
                    Console.WriteLine("The first array is earlier.");
                    break;
                }
                else if (firstArray[i] > secondArray[i])
                {
                    Console.WriteLine("The second array is earlier.");
                    break;
                }
            }
            for (int i = 0; i < minLength; i++)
            {
                if (firstArray[i] != secondArray[i])
                {
                    equalValues = false;
                }
            }
            // This is to indicate the values of the two arrays till the element of index minLength-1 are equal
            for (int i = 0; i < minLength; i++)
            {
                if (equalValues && n < m)
                {
                    Console.WriteLine("The first array is earlier.");
                    break;
                }   
                else if (equalValues && n > m)
                {
                    Console.WriteLine("The second array is earlier.");
                    break;
                }
                else if (equalValues && n == m)
                {
                    Console.WriteLine("The two arrays aree equal.");
                    break;
                }          
            }

Answer 4

这里是一个比较简单的实现，使用数组字符的ASCII值之和作为字典序比较标准：

/*  Method: compareLexicographically(a, b);
    Compare lexicographically the two arrays passed as parameters and print result.
    Comparison criteria:
    1. Arrays lengths.
    2. Accumulated ASCII values of the array characters. 
*/
static void compareLexicographically(char[] a, char[] b)
{
    if (a.Length == b.Length) // same lengths
    {
        int suma = 0;
        int sumb = 0;
        for (int i = 0; i < a.Length; i++)
        {
            suma += a[i];
            sumb += b[i];
        }

        if (suma == sumb)
        {
            Console.WriteLine("Two arrays are lexicographically equal.\n");
        }
        else
        {
            if (suma < sumb)
            {
               Console.WriteLine("First array lexicographically smaller than second.\n");
            }
            else
            {
                Console.WriteLine("First array lexicographically greater than second.\n");
            }
        }
    }
    else  // different lengths
    {
        if (a.Length < b.Length)
        {
            Console.WriteLine("First array lexicographically smaller than second.\n");
        }
        else
        {
            Console.WriteLine("First array lexicographically greater than second.\n");
        }
    }
}

Answer 5

我认为这可以解决您的问题:) 希望我也能帮到你你帮我找到了一个练习的答案

using System;

internal class CompareTwoCharArraysLexicographically
{
    private static void Main()
    {
        char[] firstArray = { 'a', 'b', 'c', 'z' };
        int firstArrayLength = firstArray.Length;
        char[] secondArray = { 'a', 'b', 'c', 'd' };
        int secondArrayLength = secondArray.Length;
        int length = Math.Min(firstArray.Length, secondArray.Length);
        bool same = false;

        if (firstArray.Length > secondArray.Length)
        {
            Console.WriteLine("Second array is earlier.");
        }

        else if (firstArray.Length == secondArray.Length)
        {
            for (int i = 0; i < length; i++)
            {
                if (firstArray[i] != secondArray[i])
                {
                    same = false;


                    if (firstArray[i] > secondArray[i])
                    {
                        Console.Clear();
                        Console.WriteLine("2 array is earlier.");
                        break;
                    }
                    if (secondArray[i] > firstArray[i])
                    {
                        Console.Clear();
                        Console.WriteLine("1 array is earlier.");
                        break;
                    }

                }



                else same = true;


                if (same == true)
                {
                    Console.Clear();
                    Console.WriteLine("Two arrays are equal."); 

                }

                else
                {
                    Console.WriteLine("First array is earlier.");
                }
            }
        }
    }
}

按字典顺序比较两个 char 数组

Compare lexicographically two char arrays

c#

arrays

compare

char