C#: Count the number of duplicate characters in a string

C# Sharp String: Exercise-60 with Solution

Write a C# Sharp program to count the number of duplicate characters (case sensitive) including spaces in a given string. If there are no duplicates, return 0.

Sample Data:
("Red Green WHITE") -> 2
("ppqrrsttuuu") -> 4
("dow jones industrial average") -> 9

Sample Solution-1:

C# Sharp Code:

using System;
using System.Linq;

namespace exercises
{
    class Program
    {
        static void Main(string[] args)
        {
            // Declare and initialize a string variable
            string text = "Red Green WHITE";

            // Display the original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));

            // Change the value of text
            text = "ppqrrsttuuu";

            // Display the new original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));

            // Change the value of text
            text = "dow jones industrial average";

            // Display the new original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));
        }

        // Define a method 'test' that takes a string argument 'text' and returns an integer
        public static int test(string text)
        {
            // Use LINQ to group characters in the string and count the number of groups with more than or equal to two occurrences
            return text.GroupBy(n => n).Count(n => n.Count() >= 2);
        }
    }
}

Sample Output:

Original String: Red Green WHITE
Number of duplicate characters in the said string: 2
Original String: ppqrrsttuuu
Number of duplicate characters in the said string: 4
Original String: dow jones industrial average
Number of duplicate characters in the said string: 9

Flowchart :

Sample Solution-2:

C# Sharp Code:

using System;
using System.Linq;

namespace exercises
{
    class Program
    {
        static void Main(string[] args)
        {
            // Declare and initialize a string variable
            string text = "Red Green WHITE";

            // Display the original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));

            // Change the value of text
            text = "ppqrrsttuuu";

            // Display the new original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));

            // Change the value of text
            text = "dow jones industrial average";

            // Display the new original string
            Console.WriteLine("Original String: " + text);

            // Display the number of duplicate characters in the string
            Console.WriteLine("Number of duplicate characters in the said string: " + test(text));
        }

        // Define a method 'test' that takes a string argument 'text' and returns an integer
        public static int test(string text)
        {
            // Using LINQ, group characters in the string and filter groups with more than one occurrence
            var t = from x in text
                    group x by x into gr
                    where gr.Count() > 1
                    select gr;

            // Return the count of such groups (representing duplicate characters)
            return (t.Count());
        }
    }
}

Sample Output:

Original String: Red Green WHITE
Number of duplicate characters in the said string: 2
Original String: ppqrrsttuuu
Number of duplicate characters in the said string: 4
Original String: dow jones industrial average
Number of duplicate characters in the said string: 9

Flowchart :

C# Sharp Code Editor:

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