Permutations of string, C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
         private static void Swap(ref char a, ref char b)
    {
        if (a == b) return;

a ^= b;
        b ^= a;
        a ^= b;
    }

public static void GetPer(char[] list)
    {
        int x = list.Length - 1;
        GetPer(list, 0, x);
    }

private static void GetPer(char[] list, int k, int m)
    {
        if (k == m)
        {
            Console.Write(list);
            Console.Write(" ");
        }
        else
            for (int i = k; i <= m; i++)
            {
                   Swap(ref list[k], ref list[i]);
                   GetPer(list, k + 1, m);
                   Swap(ref list[k], ref list[i]);
            }
    }

public static void Main(string[] args)
        {
             string str = "sagiv";
            char[] arr = str.ToCharArray();
            GetPer(arr);
        }
    }
}

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Compilation time: 0,14 sec, absolute running time: 0,09 sec, cpu time: 0,08 sec, average memory usage: 11 Mb, average nr of threads: 2