Question

How to reverse the event indexes of an array in C#

Answer 1

using System;
using System.Collections.Generic;

public class Program
{
	public static void reverseEvenIndexes(int[] arr) {
		Stack<int> stack = new Stack<int>();
		
		for (int i = 0; i < arr.Length; i += 2)	{
			stack.Push(arr[i]);
		}
		for (int i = 0; i < arr.Length; i += 2) {
			arr[i] = stack.Pop();
		}
	}

	public static void Main(string[] args)
	{
		int[] arr = new int[] {3, -1, 8, -1, 4, -1, 7, -1};

		Console.WriteLine(String.Join(' ', arr));

		reverseEvenIndexes(arr);

		Console.WriteLine(String.Join(' ', arr));
	}
}



/*
run:
 
3 -1 8 -1 4 -1 7 -1
7 -1 4 -1 8 -1 3 -1
 
*/

 

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