C#: Closest Palindrome Number

Last update on December 20 2024 12:52:00 (UTC/GMT +8 hours)

Write a C# Sharp program to find the closest palindrome number of an integer. If there are two palindrome numbers in absolute distance return the smallest number.

Sample Solution:

C# Sharp Code:

using System;
using System.Linq;
namespace exercises
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = 120;
            Console.WriteLine("Original number: " + n);
            Console.WriteLine("Closest Palindrome number of the said number: " + test(n));
            n = 321;
            Console.WriteLine("\nOriginal number: " + n);
            Console.WriteLine("Closest Palindrome number of the said number: " + test(n));
            n = 43;
            Console.WriteLine("\nOriginal number: " + n);
            Console.WriteLine("Closest Palindrome number of the said number: " + test(n));
            n = 1234;
            Console.WriteLine("\nOriginal number: " + n);
            Console.WriteLine("Closest Palindrome number of the said number: " + test(n));
        }
        public static int test(int num)
        {
            if (is_Palindrome(num)) return num;
            for (int i = 1; i <= num; i++)
            {
                if (is_Palindrome(num - i)) return num - i;
                if (is_Palindrome(num + i)) return num + i;
            }
            return 0;
        }

        public static bool is_Palindrome(int n)
        {
            string num = n.ToString();

            for (int i = 0; i < num.Length / 2; i++)
            {
                if (num[i] != num[num.Length - i - 1])
                    return false;
            }
            return true;
        }
    }
}

Sample Output:

Original number: 120
Closest Palindrome number of the said number: 121

Original number: 321
Closest Palindrome number of the said number: 323

Original number: 43
Closest Palindrome number of the said number: 44

Original number: 1234
Closest Palindrome number of the said number: 1221

Flowchart:

C# Sharp Code Editor:

Click to Open Editor

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