14. Fold and Sum

4. Fold and Sum
Read an array of 4*k integers, fold it like shown below, and print the sum of the upper and lower two rows (each holding 2 * k integers):

Examples
Input	                    Output	               Comments
5 2 3 6	                    7 9	                   5  6  +
                                                   2  3  =
                                                   7  9
1 2 3 4 5 6 7 8	            5 5 13 13	           2  1  8  7  +
                                                   3  4  5  6  =
                                                   5  5 13 13
4 3 -1 2 5 0 1 9 8 6 7 -2	1 8 4 -1 16 14	      -1  3  4 -2  7  6  +
                                                   2  5  0  1  9  8  =
                                                   1  8  4 -1 16 14
Hints
•	Create the first row after folding: the first k numbers reversed, followed by the last k numbers reversed.
•	Create the second row after folding: the middle 2*k numbers.
•	Sum the first and the second rows.

using System;
using System.Linq;

namespace _04FoldAndSum
{
    class Program
    {
        static void Main(string[] args)
        {/*
            int[] initArr = Console.ReadLine().Split(" ").Select(int.Parse).ToArray();

            int leftFoldIndex = initArr.Length / 4 - 1;
            int rightFoldIndex = 3 * initArr.Length / 4;

            int[] topArr = new int[initArr.Length / 2];

            int howManyNumbersSoFar = 0;
            for (int i = leftFoldIndex; i >= 0; i--)
            {
                howManyNumbersSoFar++;
                topArr[leftFoldIndex - i] = initArr[i];
            }
            for (int i = initArr.Length - 1; i >= rightFoldIndex; i--)
            {
                topArr[initArr.Length - 1 - i + howManyNumbersSoFar] = initArr[i];
            }


            int[] bottomArr = new int[initArr.Length / 2];

            for (int i = leftFoldIndex + 1; i < rightFoldIndex; i++)
            {
                bottomArr[i - howManyNumbersSoFar] = initArr[i];
            }


            for (int i = 0; i < topArr.Length; i++)
            {
                Console.Write(topArr[i] + bottomArr[i] + " ");
            }*/

            int[] inputArr = Console.ReadLine().Split().Select(int.Parse).ToArray();

            int k = inputArr.Length / 4;
            int[] newArr = new int[2 * k];

            for (int i = 0; i < k; i++)
            {
                newArr[i] = inputArr[k - (i + 1)] + inputArr[k + i];
                newArr[newArr.Length - 1 - i] = inputArr[newArr.Length - 1 - i + k] + inputArr[(newArr.Length - 1 - i) + (k + 2 * i + 1)];
            }
            Console.WriteLine(string.Join(" ", newArr));
        }
    }
}