Write C functions to sort a set of integers in descending order using top-down approach of merge sort code example

Example 1: merge sort c#

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

namespace Merge_sort
{    
    class Program
    {
        static void Main(string[] args)
        {
            List unsorted = new List();
            List sorted;

            Random random = new Random();

            Console.WriteLine("Original array elements:" );
            for(int i = 0; i< 10;i++){
                unsorted.Add(random.Next(0,100));
                Console.Write(unsorted[i]+" ");
            }
            Console.WriteLine();

            sorted = MergeSort(unsorted);

            Console.WriteLine("Sorted array elements: ");
            foreach (int x in sorted)
            {
                Console.Write(x+" ");
            }
			Console.Write("\n");
        }
		

        private static List MergeSort(List unsorted)
        {
            if (unsorted.Count <= 1)
                return unsorted;

            List left = new List();
            List right = new List();

            int middle = unsorted.Count / 2;
            for (int i = 0; i < middle;i++)  //Dividing the unsorted list
            {
                left.Add(unsorted[i]);
            }
            for (int i = middle; i < unsorted.Count; i++)
            {
                right.Add(unsorted[i]);
            }

            left = MergeSort(left);
            right = MergeSort(right);
            return Merge(left, right);
        }

        private static List Merge(List left, List right)
        {
            List result = new List();

            while(left.Count > 0 || right.Count>0)
            {
                if (left.Count > 0 && right.Count > 0)
                {
                    if (left.First() <= right.First())  //Comparing First two elements to see which is smaller
                    {
                        result.Add(left.First());
                        left.Remove(left.First());      //Rest of the list minus the first element
                    }
                    else
                    {
                        result.Add(right.First());
                        right.Remove(right.First());
                    }
                }
                else if(left.Count>0)
                {
                    result.Add(left.First());
                    left.Remove(left.First());
                }
                else if (right.Count > 0)
                {
                    result.Add(right.First());

                    right.Remove(right.First());    
                }    
            }
            return result;
        }
    }
}

Example 2: merge sort algo

def mergeSort(arr): 
    if len(arr) >1: 
        mid = len(arr)//2 # Finding the mid of the array 
        L = arr[:mid] # Dividing the array elements  
        R = arr[mid:] # into 2 halves 
  
        mergeSort(L) # Sorting the first half 
        mergeSort(R) # Sorting the second half 
  
        i = j = k = 0
          
        # Copy data to temp arrays L[] and R[] 
        while i < len(L) and j < len(R): 
            if L[i] < R[j]: 
                arr[k] = L[i] 
                i+= 1
            else: 
                arr[k] = R[j] 
                j+= 1
            k+= 1
          
        # Checking if any element was left 
        while i < len(L): 
            arr[k] = L[i] 
            i+= 1
            k+= 1
          
        while j < len(R): 
            arr[k] = R[j] 
            j+= 1
            k+= 1
  
# Code to print the list 
def printList(arr): 
    for i in range(len(arr)):         
        print(arr[i], end =" ") 
    print() 
  
# driver code to test the above code 
if __name__ == '__main__': 
    arr = [12, 11, 13, 5, 6, 7]  
    print ("Given array is", end ="\n")  
    printList(arr) 
    mergeSort(arr) 
    print("Sorted array is: ", end ="\n") 
    printList(arr)