Binary Search in C#

Binary Search is one of the methods of searching an item in a list of items.Here we will look into how to implement binary search in C#.

We first need to calculate the middle element in the list and then compare the element we are searching with this middle element.

To calculate middle element we use the formula:

middle element = highest element + lowest element  / 2

After we calculate the middle element we compare the element we are searching for with this element.There can be three conditions:

• if  value is equal to the middle element
• if  value is less than the middle element
• if  value is greater than the middle element


class BinarySearch
{
public static int Find(int[] numList, int val)
{

int low = 0;
int high = numList.Length-1;
int mid = 0;
while (low < =high)
{
Console.WriteLine(string.Format("low=0,high={1}",low,high));
mid = high +low/ 2;

if (val == numList[mid])
{
Console.WriteLine(string.Format("found value"));
return mid;
}
if (val > numList[mid])
{
Console.WriteLine(string.Format("value is less than the middle element"));
low = mid + 1;

Console.WriteLine(string.Format("low=0,high={1},mid={2}", low, high, mid));
}
else
{
Console.WriteLine(string.Format("value is greater than the middle element"));
high = mid - 1;
}

}

return -1;

}
}

 

 

public static void Main()
{
var location = BinarySearch.Find(new int[] { 1, 2, 3, 4,5,6,7,8,9 }, 6);
Console.WriteLine(location);

}


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