C# 查找数组中重复字符的数量并列出它们

Question

我正在尝试查找数组中重复字符的数量并列出它们。例如，用户输入“这是我的房子”，输出应该如下所示：

重复字符数为：3，重复项为：h i s

我必须使用ToCharArray()

我一直在尝试，但无法让它正常工作，你能帮忙吗？

谢谢

这是我的代码：

---

using System;
class Program
{
    static void Main()
    {
        Console.Write("type a sentence: ");
        String str = Console.ReadLine();
        char[] arr = str.ToCharArray();

        for (int j = 0; j < arr.Length; j++)
        {
            for (int k = j + 1; k < arr.Length; k++)
            {
                if (arr[j] == arr[k] && j != k)
                {
                    Console.WriteLine("number of duplicates: " + k + "\n" + "duplicates are: " + arr[j]);
                    Console.ReadLine();
                }
            }
        }
    }
}

---

Answer 1

你可以尝试使用linq代替for循环。

GroupBy

建立一个组并使用

where

得到

count

大于 1。

var r= str.Replace(" ", "").GroupBy(_ => _).Where(x => x.Count() > 1).Select(x => x.Key);

然后使用

string.Join

方法和 linq

count

而不是循环来获得您期望的结果。

Console.Write("type a sentence: ");
String str = Console.ReadLine();


var result = str.Replace(" ", "")
     .GroupBy(_ => _)
     .Where(x => x.Count() > 1)
     .Select(x => x.Key);


Console.WriteLine("number of duplicates: " + result.Count() + "\r" + "duplicates are: " + string.Join(" ",result));

c#在线

结果

type a sentence: number of duplicates: 3  duplicates are: h i s

Answer 2

这是另一种没有 linq 的解决方案：

static void Main(string[] args)
{
    string longText = @"your sentence comes here";
    foreach (var character in CharacterCount.Count(longText))
    {
        if(character.Value>1)
           Console.WriteLine("{0} - {1}", character.Key, character.Value);
    }    
}

class CharacterCount
{
    public static SortedDictionary<char, ulong> Count(string stringToCount)
    {
        SortedDictionary<char, ulong> characterCount = new SortedDictionary<char, ulong>();

        foreach (var character in stringToCount)
        {
            if (!characterCount.ContainsKey(character))
                characterCount.Add(character, 1);
            else
                characterCount[character]++;
        }
        return characterCount;
    }   
}  

Answer 3

这可能会有所帮助。

    Console.Write("type a sentence: ");
    String str = Console.ReadLine();
    char[] arr = str.ToCharArray();

    int[] count = new int[10000];

    for (int j = 0; j < arr.Length; j++)
    {
        if( arr[j] >= 'a' && arr[j] <= 'z' || arr[j] >= 'A'&& arr[j] <= 'Z' )
        {
            count[arr[j]]++;
        }
    }

    int ans=0;
    for (int j = 0; j < count.Length; j++)
    {
        if(count[j]>1)
        {
            ans++;              
        }
    }

    Console.Write("Number of duplicates: " + ans +" duplicates are: ");

    for (int j = 0; j < count.Length; j++)
    {
        if(count[j]>1)
        {
            Console.Write((char)j +" " );
        }
    }
    Console.WriteLine();
}

Answer 4

This Find to find Duplicates characters And Its Occurrence and I am using Key value pair in C# 
    /// <summary>
    /// Find The Duplicates And Its Occurrence
    /// </summary>
    /// <param name="inputString"> input String for example 
    /// "Aassekoopannessyttoodde","Mississippi","raccoonnookkeeper"</param>
    private static void FindTheDuplicatesAndItsOccurrence(string inputString)
    {
        // we used Dictionary to make this collection generic  
        Dictionary<Char, int> CharCount = new Dictionary<char, int>();

        foreach (Char eachLetter in inputString)
        {
            if (eachLetter != ' ')
            {
                if (!CharCount.ContainsKey(eachLetter))
                {
                    CharCount.Add(eachLetter, 1);
                }
                else
                {
                    CharCount[eachLetter]++;
                }
            }
        }
        
        foreach (var item in CharCount)
        {
            if (item.Value > 1)
            {
                Console.WriteLine(item.Key + "," + item.Value);
            }
            
        }
    }

Answer 5

    **finding duplicate characters and there count using linq **
    using System;
    using System.Linq;
    using System.Collections.Generic;
                        
    public class Program
    {
        public static void Main()
        {
            string myName = "Hussamuddin";
            List<char> elementCount =  new List<char>(myName.ToCharArray());
            var mycount = elementCount.Where(x => myName.Contains(x)).GroupBy(x=>x).Where(x => x.Count()>1).Select(x => x.Key + ":" + x.Count().ToString()).ToList();
            mycount.ForEach(x => Console.WriteLine(x));
        }
    }

Output :
u:2
s:2
d:2