for Codility PermCheck

PermCheck.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PermCheck
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] A = { 4, 1, 3, 2 };
            int[] B = { 4, 1, 3 };
            Solution sol = new Solution();
            Console.WriteLine(sol.solution(A));
            Console.WriteLine(sol.solution(B));
        }
    }

    public class Solution
    {
        public int solution(int[] input)
        {
            int isPermutation = 0;
            bool[] checkList = new bool[input.Length + 1];
            int count = 0;

            for (int i = 0; i < input.Length; i++)
            {
                if (input[i] > input.Length)
                {
                    break;
                }

                if (!checkList[input[i]])
                {
                    checkList[input[i]] = true;
                    count += 1;
                }
            }

            if (count == input.Length)
            {
                isPermutation = 1;
            }
            return isPermutation;
        }
    }
}