C#: Check a given array of integers and return true if every 5 that appears in the given array is next to another 5

Last update on June 28 2025 12:54:00 (UTC/GMT +8 hours)

Check If Every 5 is Next to Another 5

Write a C# Sharp program to check a given array of integers. Return true if every 5 in the given array is next to another 5.

Visual Presentation:

Sample Solution:

C# Sharp Code:

using System; // Importing the System namespace

namespace exercises // Defining a namespace called 'exercises'
{
    class Program // Defining a class named 'Program'
    {
        static void Main(string[] args) // The entry point of the program
        {
            // Outputting the results of the 'test' method with different integer arrays as arguments
            Console.WriteLine(test(new[] { 3, 5, 5, 3, 7 })); // Testing the method with various arrays
            Console.WriteLine(test(new[] { 3, 5, 5, 4, 1, 5, 7 })); // Testing the method with various arrays
            Console.WriteLine(test(new[] { 3, 5, 5, 5, 5, 5 })); // Testing the method with various arrays
            Console.WriteLine(test(new[] { 2, 4, 5, 5, 6, 7, 5 })); // Testing the method with various arrays
        }

        // Method to check if '5' exists in the array but not adjacent to another '5'
        static bool test(int[] numbers)
        {
            int arr_len = numbers.Length; // Storing the length of the array
            bool flag = true; // Initializing a flag to true

            for (int i = 0; i < arr_len; i++) // Looping through the elements of the array
            {
                if (numbers[i] == 5) // Checking if the current element is '5'
                {
                    if ((i > 0 && numbers[i - 1] == 5) || (i < arr_len - 1 && numbers[i + 1] == 5)) // Checking if '5' is adjacent to another '5'
                        flag = true; // Setting the flag to true if '5' is adjacent to another '5'
                    else if (i == arr_len - 1) // Checking if '5' is the last element in the array
                        flag = false; // Setting the flag to false if '5' is the last element and not adjacent to another '5'
                    else
                        return false; // Returning false if '5' is not adjacent to another '5'
                }
            }
            return flag; // Returning the flag value
        }
    }
}

Sample Output:

True
False
True
False

Flowchart:

Go to:

• C# Sharp Basic Algorithm Exercises Home ↩
• C# Sharp Programming Exercises Home ↩

PREV : Check for 5 Exactly Five Times Without Adjacent.
NEXT : Check Equal Elements at Start and End.

C# Sharp Code Editor:

Improve this sample solution and post your code through Disqus