Min max elements swap of the array, 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
    {
        public static void Main(string[] args)
        {
            int [] arr = { 1, 2, 3, 4, 5, 6 }; 
            Console.Write("The array is  : " ) ;
            Display(arr);
            MinMaxSwap(arr);
            Console.Write("After min max swap  : " ) ;
            Display(arr);
        }
        
        public static void MinMaxSwap(int[] input) {
            if (input.Length == 0)
                return;

int maxIndx = 0;
            int minIndx = 0;
            for (int i = 1; i < input.Length; i++) {
                if (input[maxIndx] > input[i])
                    maxIndx = i;
                if (input[minIndx] < input[i])
                    minIndx = i;
            }
            int valMax = input[maxIndx];
            input[maxIndx] = input[minIndx];
            input[minIndx] = valMax;
        }

public  static void Display(int []arr) { 
            int n = arr.Length; 
            for (int i = 0; i < n; ++i) 
                Console.Write(arr[i] + " "); 
            Console.WriteLine(); 
         }
    }
}

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Compilation time: 0,31 sec, absolute running time: 0,2 sec, cpu time: 0,17 sec, average memory usage: 15 Mb, average nr of threads: 3, absolute service time: 0,54 sec