Question

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

Answer 1

using System;
using System.Collections.Generic;

public class Program
{
	public static void reverseOddIndexes(int[] arr) {
		Stack<int> stack = new Stack<int>();
		
		for (int i = 1; i < arr.Length; i += 2) {
			stack.Push(arr[i]);
		}
		for (int i = 1; i < arr.Length; i += 2) {
			arr[i] = stack.Pop();
		}
	}

	public static void Main(string[] args)
	{
		int[] arr = new int[] {-1, 9, -1, 0, -1, 7, -1, 5};

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

		reverseOddIndexes(arr);

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




/*
run:
 
[-1, 9, -1, 0, -1, 7, -1, 5]
[-1, 5, -1, 7, -1, 0, -1, 9]
 
*/

 

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