I'm trying to make a scan of an array where it follows the index with the numbers inside and I don't understand why it gives me this exception. I cant add any more details its a pretty straight forward question.

using System;
                    
public class Program
{
    public static bool IsPerfect(int[] arr)
        {
            int next=0, done=0,i;

            while (done == 0)
            {
                i = arr[next];
                arr[next] = 10;
                next = arr[i];

                if (i == 0)
                    done = 1;
            }

            for(int j = 0; j < arr.Length; j  )            
                if (arr[j] != 10)
                    return false;               
            return true;

          
        }
        
    
    public static void Main()
        {
            int[] arr = { 3, 0, 1, 4, 2 };
            if (IsPerfect(arr) == true)
                Console.WriteLine("is perfect");
            if (IsPerfect(arr) == false)
                Console.WriteLine("boooo");

        }
}

CodePudding user response：

You are not specifying the functioning for duplicates... Use a method to check for duplicates and as soon as you encounter a duplicate element exit the loop... It will work fine!