C#: Number of times a substring appeared in a string

Last update on August 25 2025 12:50:18 (UTC/GMT +8 hours)

Write a C# Sharp program that takes a string that repeats a substring. Count the number of times the substring appears.

Sample Data:
("aaaaaa") -> 6
("abababab") -> 4
("abcdabcdabcd") -> 3

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 = "aaaaaa";

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared in the said string: " + test(text));

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

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared in the said string: " + test(text));

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

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared 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)
        {
            // Split the string by its first character, then count the number of resulting substrings
            // The number of times a substring appeared in the string is equal to the count of substrings minus 1
            return text.Split(text[0]).Count() - 1;
        }
    }
}

Sample Output:

Original strings: aaaaaa
Number of times a substring appeared in the said string: 6
Original strings: abababab
Number of times a substring appeared in the said string: 4
Original strings: abcdabcdabcd
Number of times a substring appeared in the said string: 3

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 = "aaaaaa";

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared in the said string: " + test(text));

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

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared in the said string: " + test(text));

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

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

            // Display the number of times a substring appeared in the string
            Console.WriteLine("Number of times a substring appeared 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)
        {
            // Find the index of the first character of the string starting from index 1 (excluding the first character)
            int ctr = text.IndexOf(text[0], 1);

            // If the index is less than 0, return 1 (as there's only one repeated substring)
            // Otherwise, return the length of the string divided by the index of the second occurrence
            return ctr < 0 ? 1 : text.Length / ctr;
        }
    }
}

Sample Output:

Original strings: aaaaaa
Number of times a substring appeared in the said string: 6
Original strings: abababab
Number of times a substring appeared in the said string: 4
Original strings: abcdabcdabcd
Number of times a substring appeared in the said string: 3

Flowchart :

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