Modify the C# code in exercise 1 in order to search for an element of the array using binary search algorithm.

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

namespace Csharp_exercises
{
class Program
{
static void Main(string[] args)
{

int[] arr = new int[10] { 23, 2, 3, 34, 6, 1, 24, 45, 78, 8 }; //unsorted data set
int pos, target;
Console.Write("Enter value to find:");
target = int.Parse(Console.ReadLine());
pos = binsearch(arr, 23, 10);
if (pos != -1)
Console.WriteLine("The target item was found at location:{0}", pos);
else
Console.WriteLine("The target item was not found in the list.\n");
Console.ReadLine();

}

///binary search
static int binsearch(int[] dataset,int target, int l,int u){
  insertsort(dataset,dataset.Length);//make sure the list sorted
  while(u>=l){  

    int mid=(l+u)/2;  

    if(target==dataset[mid]) return mid;  

    else if(target>dataset[mid]) l=mid+1;  

    else if(target<dataset[mid]) u=mid-1;  

}
return -1;
}

static void insertsort(int[] dataset, int n)
{

int i, j;
for (i = 1; i < n; i++)
{
int pick_item = dataset[i];
int inserted = 0;
for (j = i - 1; j >= 0 && inserted != 1; )
{
if (pick_item < dataset[j])
{
dataset[j + 1] = dataset[j];
j--;
dataset[j + 1] = pick_item;
}
else inserted = 1;
}
}

}
}
}