using System;
namespace BinarySearch
{
class Program
{
static void Main(string[] args)
{
int[] a = new int[] { 2, 4, 6, 8, 9 };
Console.WriteLine(BinarySearchIterative(a, 9));
Console.WriteLine(BinarySearchRecursive(a, 9, 0, a.Length));
}
private static int BinarySearchIterative(int[] a, int val){
int low = 0;
int high = a.Length;
while (low <= high)
{
int mid = (low + high) / 2;
if (a[mid] > val)
high = mid-1;
else if (a[mid] < val)
low = mid+1;
else
return mid;
}
return -1;
}
private static int BinarySearchRecursive(int[] a, int val, int low, int high)
{
if (high < low)
return -1;
int mid = (low + high) / 2;
if (a[mid] > val)
return BinarySearchRecursive(a, val, low, mid - 1);
else if (a[mid] < val)
return BinarySearchRecursive(a, val, mid + 1, high);
else
return mid;
}
}
}