Question

Problem:

I am trying to implement a binary search function in Visual Studio 2019 using C#. This is my first program in C# and I translated it from Java.

In this program, I am to carry out the same 10,000,000 unsuccessful searches for eight different-sized arrays, namely arrays of sizes, 128, 512, 2048, 8192, 32768, 131072, 524288, and 2,097,152. I need to measure each of the three programs and the time it takes to do the 10,000,000 searches for each of the eight arrays. Compare the timings to the theoretical timings the algorithm binary search provides.

Please make corrections to my programs below so that it may successfully debug/run.

Code:

using System;
class BinarySearch
{
   int BinarySearch(int arr[], int 1, int r, int x)
   {
       if (r >= 1)
       {
           int mid = 1 + (r - 1) / 2;
           if (arr[mid] == x)
               return mid;
           if (arr[mid] > x)
               return BinarySearch(arr, 1, mid - 1, x);
           return BinarySearch(arr, mid + 1, r, x);
       }
       return -1;
   }

   public class Problem5InC#
   {

       public static void main(String[] args)
       {

           BinarySearch obj = new BinarySearch();
           int size = 2097152;
           int arr[] = new int[size];
           for (int i = 0; i < size; i++)
           {
               arr[i] = 0;
           }
           int x = 1;
           int result = 0;
           long start = System.currentTimeMillis();
           for (int i = 0; i < 10000000; i++)
           {
               result = obj.BinarySearch(arr, 0, size - 1, x);
           }
           long end = System.currentTimeMillis();
           long elapsed_time = end - start;
           Console.write("elapsed_time");
       }
   }

Answer 1

using System;

using System.Diagnostics;

class MainClass

{

static int search(int[] arr, int l, int r, int x)

{

if (r >= 1)

{

int mid = 1 + (r - 1) / 2;

if (arr[mid] == x)

return mid;

if (arr[mid] > x)

return search(arr, 1, mid - 1, x);

return search(arr, mid + 1, r, x);

}

return -1;

}

public static void Main (string[] args) {

{

int size = 2097152;

int[] arr = new int[size];

for (int i = 0; i < size; i++)

{

arr[i] = 0;

}

int x = 1;

int result = 0;

Stopwatch stopwatch = new Stopwatch();

stopwatch.Start();

for (int i = 0; i < 10000000; i++)

{

result = search(arr, 0, size - 1, x);

}

stopwatch.Stop();

TimeSpan stopwatchElapsed = stopwatch.Elapsed;

Console.WriteLine(Convert.ToInt32(stopwatchElapsed.TotalMilliseconds));

}

}

}