C#: Smallest positive which is not present in an array

C# Sharp Array: Exercise-40 with Solution

Write a C# Sharp program that takes an array of integers and finds the smallest positive integer that is not present in that array.

Sample Data:
({ 1,2,3,5,6,7}) -> 4
({-1, -2, 0, 1, 3, 4, 5, 6}) -> 2

Sample Solution:

C# Sharp Code:

using System;
using System.Linq;
namespace exercises
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] nums1 = {1,2,3,5,6,7};
            Console.WriteLine("Original array elements:");
            Console.WriteLine($"{string.Join(", ", nums1)}");
            Console.WriteLine("Smallest positive which is not present in an array: " + test(nums1));
            int[] nums2 = {-1, -2, 0, 1, 3, 4, 5, 6};
            Console.WriteLine("\nOriginal array elements:");
            Console.WriteLine($"{string.Join(", ", nums2)}");
            Console.WriteLine("Smallest positive which is not present in an array: " + test(nums2));
        }
        public static int test(int[] nums)
        {
            int i = 1;
            while (true)
            {
                if (!(nums.Count(v => v == i) > 0)) 
                    return i;
                i++;
            }
        }
    }
}

Sample Output:

Original array elements:
1, 2, 3, 5, 6, 7
Smallest positive which is not present in an array: 4

Original array elements:
-1, -2, 0, 1, 3, 4, 5, 6
Smallest positive which is not present in an array: 2
 

Flowchart:

C# Sharp Code Editor:

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