C#: Prime number in strictly ascending decimal digit order

Last update on December 20 2024 12:46:53 (UTC/GMT +8 hours)

Primes in Ascending Order

Write a C# Sharp program to create and display all prime numbers in strict ascending decimal digit order.

Sample Data:
2, 3, 5, 7, 13, 17, 19, 23, 29, 37, 47, 59, 67, 79,

Sample Solution:

C# Sharp Code:

using System;
using System.Collections.Generic;

namespace exercises
{
    class Program
    {
        // Method to check if a number is prime
        public static bool IsPrime(uint n)
        {
            if (n <= 1)
            {
                return false;
            }

            int ctr = 0;
            for (int i = 1; i <= n; i++)
            {
                if (n % i == 0)
                {
                    ctr++;
                }
                if (ctr > 2)
                {
                    return false;
                }
            }

            return true;
        }

        static void Main(string[] args)
        {
            var Q = new Queue<uint>(); // Queue to store numbers
            var prime_nums = new List<uint>(); // List to store prime numbers

            // Enqueue initial numbers from 1 to 9 into the queue
            for (uint i = 1; i <= 9; i++)
            {
                Q.Enqueue(i);
            }

            // Continue while the queue is not empty
            while (Q.Count > 0)
            {
                // Dequeue a number
                uint n = Q.Dequeue();

                // Check if the dequeued number is prime and add it to the list of prime numbers
                if (IsPrime(n))
                {
                    prime_nums.Add(n);
                }

                // Enqueue the next potential prime numbers formed by appending digits from 1 to 9
                for (uint i = n % 10 + 1; i <= 9; i++)
                {
                    Q.Enqueue(n * 10 + i);
                }
            }

            // Display the generated prime numbers
            foreach (uint p in prime_nums)
            {
                Console.Write(p);
                Console.Write(", ");
            }
            Console.WriteLine();
        }
    }
}

Sample Output:

2, 3, 5, 7, 13, 17, 19, 23, 29, 37, 47, 59, 67, 79, 89, 127, 137, 139, 149, 157, 167, 179, 239, 257, 269, 347, 349, 359, 367, 379, 389, 457, 467, 479, 569, 1237, 1249, 1259, 1279, 1289, 1367, 1459, 1489, 1567, 1579, 1789, 2347, 2357, 2389, 2459, 2467, 2579, 2689, 2789, 3457, 3467, 3469, 4567, 4679, 4789, 5689, 12347, 12379, 12457, 12479, 12569, 12589, 12689, 13457, 13469, 13567, 13679, 13789, 15679, 23459, 23567, 23689, 23789, 25679, 34589, 34679, 123457, 123479, 124567, 124679, 125789, 134789, 145679, 234589, 235679, 235789, 245789, 345679, 345689, 1234789, 1235789, 1245689, 1456789, 12356789, 23456789,

Flowchart:

C# Sharp Code Editor:

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