Single complete cycle

isSCC

using System;

// Determine whether a circular array of relative indices is composed 
// of a single complete cycle
// ToDO - Do it O(1) space

namespace SingleCompleteCycle
{
    public class Program
    {
        public static void Main(string[] args)
        {
            test(new int[]{ 2, 2, -1 });
            test(new int[]{ 1, -2, 1 });
            test(new int[]{ 1, 2, 3 });
            test(new int[]{ 1, -6, 7, 2 });
            test(new int[]{ -6, 1, 3 });
        }
        
        static void test(int[] arr) {
            Console.WriteLine("Is SCC: {0}", isSCC(arr));
        }
        
        static bool isSCC(int[] arr) {

            if (arr.Length == 0) {
                return false;
            }
            
            bool[] visited = new bool[arr.Length];
            
            int current = 0;
            
            int count = 0;
            
            while (count < arr.Length) {
                if (current >= 0) {
                    current = (current + arr[current]) % arr.Length;   
                }
                
                while (current < 0) {
                    current += arr.Length;
                }
                
                visited[current] = true;
                
                count++;
            }
            
            for(int i = 0; i < visited.Length; i++) {
                if (!visited[i]) {
                    return false;
                }
            }
            
            return true;
        }
        
    }
}